Maybe one of these SOLD VERY RARE BRITISH MILITARY ISSUE COLT 1903 POCKET HAMMERLESS PISTOL.......SOE & RAF USE IN WW2 | Pre98 Antiques
A number of Colt Pocket Model automatic pistols (M1903/08 series) in .32 were used by British forces. Other candidates include Llama automatic pistols in .32 (which went to SOE and apparently to resistance movements) and the Webley police model automatic (used by the Met and other forces). That's if the round is from the WWII era.
The .32 ACP round is not listed as a British service cartridge on https://sites.google.com/site/britmilammo/home. Alas, the founder of the site, the brilliant Tony Edwards, did not live long enough to add some of the odd cartridges which did show up in British service. Kynoch, Britain's leading ammo maker, made a wide range of cartridges of all types for commercial sale well into the postwar years. Since .32 was very popular worldwide I'd be surprised if they hadn't made it at some point post 45. As far as postwar .32 weapons in British service the only one I can think of is the Walther PPK, examples of which went to the constabulary in Northern Ireland. I don't know if any .32 Colt Pocket Models were still hanging around after WWII, but if they were I wouldn't be surprised.
