Simple commercial cover to Germany, 1F50 in French 1925 issue stamps looks quite a lot for a simple cover but it very surely is not philatelic. Left separator bar of the cancel is broken so this should be PCH type 9B.
Interesting: This gun-powder factory Hasloch exploded the second time in 1928 after 1920 and was never rebuilt as a gun-powder factory. It became a furniture company. So this letter was sent in vain I guess. (Klinger coll.)

Letter to Dunedin, New Zealand. The 50c and 10c stamps are cancelled with PCH type 12. I don't know when in 1937 the rate to NZ went up to 60c. (Klinger coll.)

Letter to Dunedin, New Zealand. The 50c and 10c stamps are cancelled with PCH type 12. Same cover as before. ("Sesi" coll.)

Letter to Dunedin, New Zealand. The 50c and 10c stamps are cancelled with PCH type 12. Same cover as before. (seen at some internet auction)

Compagnie des Messageries Maritimes letter from Vila to Marseille France . The British 5d stamp cancelled with PCH type 15 . Machine cancel MARSEILLE ARRIVEE 19-11-1937 FUMEZ/LES CIGARETTES/CELTIQUES on arrival. ("SeSi" collection).

12 January 1937

Cover with 2 x 2 1/2d British issue from Vila to Paris, France, tied by New Hebrides/Vila cds 1 March 1937, PCH type 10A, not recorded there for this date. Backstamped at arrival Paris 2, 24 April 1937. (Klinger coll.)

1 March 1937

Postcard to Hongcong. Two mixed 25c stamps cancelld with GK PM7A. Overpaid 10c.
Image thanks to Gary & Nancy DuBro, Compustamp

Letter to New York USA, the British 2d. and 2/- stamps tied by PCH type 11. Mirror of backstamp in Tahiti on front and Daguin machine cancel VISITEZ TAHITI PERLE DU PACIFIQUE , PAPEETE ILE TAHITI 2.6.37 in transit on back. ("SeSi" collection).

12 May 1937

2F 70c French issue on a letter to New York City, tied with pch type 11. Must have been a heavy letter. Backstamped Papeete 2 June 1938 with a slogan canceller "Visitez Tahiti Perle du Pacifique". (Klinger coll.)

12 May 1937

Two French 25c stamps on a commercial cover to Noumea. They are cancelled with PCH Type 10. Backstamped Noumea 31 5 37. (Klinger coll.)

Two French 30c and 20s stamps on a commercial cover to the U.S.A. cancelled with GK Type PM7C. Franked with the colonial letter rate 50c instead of the non-colonial one 1F50c but not taxed.
Image thanks to Steve Drewett & Empire Stamp Auctions

Registered letter from Vila to Ravenburg Germany. The five 30c stamps tied by GK type PM7B. Correct 1F50c non colonial rate for a letter up to 20g but here there is a registration label type NR10B (rate 1F50). May be a mix-up with the British 6d stamp which is nearer this color or as the manuscript "Catalogue only" suggests there was a printed matter rate we don't know of so far. Backstamped GPO SYDNEY RS 23 JY 37 in transit and RAVENSBURG 29.8.37 on arrival.
Interesting question: Rugel & Lutz Ravensburg was well known for their wood working machinery. You'd rather suppose that catalugues were sent to the New Hebrides and not back to the company - or maybe only a page of the catalogue was sent with an order. ("SeSi" coll.)

6 July 1937

Two French 30c and 20s stamps on a commercial cover London. (Seen in an old auction)

1F 50c on a letter to the U.S. Norfolk customs handstamp at left. (old auction)

PPC to France, the 25c stamp cancelled with GK type PM7B. Correctly franked colonoal short message postcard rate. (ex Millet coll.)

13 August 1937

Cover with a 5d British issue from Vila to Marseilles, France, tied by New Hebrides/Vila cds 19 August 1937, PCH type 9. (Merot coll.)

Cover franked 55c to the U.S. cancelled PM7B and taxed there. Non colonial letter rate in 1937 was 1F50c.

Cover with 50c colonial letter rate cancelled with GK type PM7B to Australia. (ex Millet coll.)

Standard cover to Abidjan, Côte d'Ivoire (Ivory Coast) at the 50c colonial rate. Cancelled with GK type PM7B. A.O.F. means Afrique-Occidentale Française. No markings on the back.
Image thanks to David Moss and Northwich Philatelic Society | Northwich, Cheshire.

Letter to Perpignan (Pyrénées orientales) France. The French 20c. and 5c.(2), the British 2d. stamp tied by PCH type 9B. Backstamped Perpignan 18 XII 37. ("SeSi" collection)

Parcel tag with 6 English 50c stamps on reverse cancelled with GK Type PM7B. Registration cachet GK Type NR9.
Image thanks to David Moss and Northwich Philatelic Society | Northwich, Cheshire.

9 November 1937
(new 2/2019)

Parcel tag with 6 English 50c stamps on reverse cancelled with GK Type PM7B. Registration cachet GK Type NR9.
Image thanks to ESA Auctions

9 November 1937
(new 2/2019)

Parcel tag with 6 English 25c stamps on reverse cancelled with GK Type PM7B. Registration cachet GK Type NR9.
Image thanks to Chris Rainey

9 November 1937

Parcel tag with a total of 13F cancelled with GK Type PM7B. Registration cachet GK Type NR9. (ex Millet coll.)>

9 November 1937

Parcel tag with a French 1F stamp on front and an imprint block of 6 1F25c stamps on revrse all cancelled with GK Type PM7B. Registration cachet GK Type NR9. Image thanks to Lugdunum Philatélie

9 November 1937

Parcel tag with 2/- and 5/- stamps French 1F stamp on front and an imprint block of 6 1F25c stamps on revrse all cancelled with GK Type PM7B. Registration cachet GK Type NR9. (ex Millet coll.)

9 November 1937

Air Mail cover to N.S.W. with a French 1F stamp. But I doubt that it went by Air Mail as pre-war Air Mail needed much more postage. (Goron coll.) Same sender and addressee as of cover [C.1.5.7-38FE02]

Nice commercial cover from Gubbay Frères, destiny unknown thanks to the window cover. The 10c and 40c stamps are cancelled with PCH type 10A. (Goron coll.)

Correct 5d colonial rate to Burwood NSW on 28 DEC 37 (type PM7A) and additionalyy cancelled with 19 JAN 38 Sydney circular box. Forwarded to Hobart on 19 JAN 38 and then back to Sydney on 24 JAN 1938.
Backstamped 19 January 1938 Sydney suburban box machine slogan and Hobart machine slogan 24 January 1938. ("SeSi" coll.)

28 December 1937
(new 4 March 2018)

Letter from Vila to Colton Oregon. The stamps tied by GK type PM7B, correct 1F50c rate to USA. ("SeSi" coll.)

Letter (KPM - Koninklijke Paketvaart Maatschappij Netherlands - cover) to Lindfield, N.S.W. All stamps different cancelled with GK Type PM7B. Addressee is Dr. W.L. Waterhouse, wheat research worker at Sydney University. (Image thanks to Gaertner Auctions )

KPM sign

Another letter (KPM - Koninklijke Paketvaart Maatschappij Netherlands - cover) to Lindfield, N.S.W. Three other different stamps cancelled with GK Type PM7B. Addressee is Dr. W.L. Waterhouse, wheat research worker at Sydney University. (Image thanks to Gaertner Auctions )

KPM sign

Letter to Burwood, NSW, Australia, the 60c stamp cancelled with PCH type 10. Same sender and addressee as of cover [C.1.5.7-37NO29]. (Goron coll.)

Cover with a French 1F and a British 6d stamp cancelled with PCH type 10. The change to gold currency made the sixth part out of this so the letter was prepaid 27 cg in gold currency. The Swiss post officials made a tax of 5c out of this on 26 March 1938 in Geneva. (Goron coll.)

Letter with British 6d stamp from the French hospital in Vila to Nouméa.
Cancelled with PCH type 9B. Backstamped Noumea 14-2 38. (Klinger coll.)

Letter to France from the Catholic Mission. Correctly paid with 1925 60c which equal to 10cg in 1938. Interesting that 1938 being no leap year Vily decided that the calender needed a four days correction: cancelled on 32 FE 38 with type 15A. ("SeSi" coll.).

Registered letter to England. Image thanks to Sandafayre Stamp Auctions

Registered letter to France. Slightly overpaid as 1F60c would have been enough. (Seen in an old auction)

Registered letter from Vila to Seattle, U.S.A. with a total of 2F95c cancelled with PM7A. Backstamped Sydney RS 9 April 1938 snd Seattle 6 and 7 May 1938.

1 April 1938
(new 7/2018)

Letter from Vila to the well known physician Frank (Francis John) Douglas (1873-1964) in Victor Harbour, South Australia. Very late but correct use of a 1925 British issue. Some weeks later (on 1st June) the virtual gold currency was intrduced. The 6d stamp tied by GK type PM7B. ("SeSi" coll.)

Registered (typewriter O.H.M.S.) cover to England. The cover ist still franked with the 1937 rate (50c and reg. 1F). Cancelled GK type PM7B, backstamped Sydney 9 April.
Image thanks to David Moss and Northwich Philatelic Society | Northwich, Cheshire.

Letter with British 6d stamp from the French hospital in Vila to Nouméa.
Image thanks to Soler y Llach, Spain

Letter with French 70c to France. Colonial letter rate was 60c in 1938 so overpaid 10c.

23 May 1938
(new 1/2021)

Local letter from Mère Marie Alexis in Port Vila to Olal, Ambrym. The mixed 1925 60c postage matches the correct 10cg postage for a local letter. (Klinger coll.)

Cover from the New Hebrides to Manchester. Correct franking was 10cg oder six times the amount in old Cents : 60c old. So underfranked 10c old. Anyway - the cover was posted in Sydney together with an Australian 2d stamp and cancelled "Posted in pilar box" in Sydney. Image thanks to David Moss and Northwich Philatelic Society | Northwich, Cheshire.

Registered letter to Maison Carrée Algeria. The French 1F and 20c., the British 6d. stamp tied by PCH type 9B.The registration label is PCH type R11. As the currency had changed to the Gold Franc, the the 1F80c had to be divided by 6 and the resulting 30c paid the correct rate: 10cg to France and 20cg registration. Backstamped Maison Carrée 23-1-39. ("SeSi" collection)

Even later - and uncensored! PCH types 11 and 12 on 1925 French 10c and 5c, British 1d and ½d: cover to the U.S.A. Correct 30c letter rate but not paid in Franc gold but with the old 1925 stamps. Nobody objected. The addressee was a member of the United States' gold medal-winning rugby team at the 1920 Olympic Games in Antwerp and for 20 years coach at Burlingame High School. (Klinger coll.)

A rather late use: PCH type 21 on a 1925 French 20c stamp: cover to Canada, taxed rather low with 40c. Handstamped "Nouvelles - Hébrides / Délégation Française / T A N N A." This cover is from the French District Agent (FDA) on Tanna. At that time, Tanna didn't have it's own cancel, so everything got cancelled in Vila. (Seen in a 1992's dealers offer)

A rather scarce use of ½d, 1d & 1½d Gilbert & Ellice Islands stamps in Vila. Maybe ship mail but no paquebot handstamp available or just tolerated. Underpaid as colonial letter rate was 6d from January 1938 to May 1938. Image thanks to Steve Drewett Postal History