Dabney-
That suggestion to buy Boothroyd's, The Handgun came from me. I don't think Andrew has ever seen a copy. He was quoting from one of my posts. I've been preaching here about that book and Keith's, Sixguns for years. I'm always glad when someone orders a copy. I think it's out of print, but has never been widely publicized in the USA and prices are not high. It's about the size of many phone books, so don't drop it on your toes!

I think you'll be astounded at the range of content and the excellence of that coverage.
You can see an Enfield .38 in, The Purple Plain with Gregory Peck and in ,The Guns of Navarone, carried by David Niven. Amusingly, Niven played a corporal. In real life, the actor became a Lt. Col. or a full Colonel; I forget which. Before he became an actor, he was a British officer and was recalled to duty for WWII. In his autobiography he referred to his revolver as a Webley. Probably a MK VI, as he owned it before the war. Issue of the then-new Enfield seems to have begun by 1931, perhaps earlier. It was adopted in 1927, but replacement was gradual and not all those equipped with revolvers had the .38 by 1939. BTW, Anthony Quinn also had an Enfield .38 in that film, holding it ready behind a newspaper as he met a guest who might be a German agent. The guns in the film are not the same as in the book, which I think was written by Alistair MacLean. Oddly, the book mentioned just one Colt. It would have been a .45 auto, but British special ops personnel usually carried that arm, and not just one per party. If you see, The Guns of Navarone, look for the Mauser .32 in the hand of one German officer. Because his hand hides the handle, I can't say if it was the M-1914 or the later M-1934. The latter has a more curved rear part of the handle.
This film is on DVD and is one of the very best of all WWII movies. I recall seeing it in the theater when it was released. Yeah, I was interested in this stuff at an early age.
I've seen photos of tank crews with the new .38's in the mid 1930's and in the film, Drums, you can also see the Pattern 37 webbing holsters. Pretty odd, as that movie appeared that year, I think, and was set in India. Maybe there was already a very similar holster in use?
I have long been interested in the British military in the 20th Century, when they still held much of their wide Empire. I look for mentions of both rifles and handguns in books, and for photos in magazines like, Life and National Geographic. Those are, of course, also very useful for those of you interested in the S&W Victory Model .38's.
A cover of Newsweek (?) showed the late King Hussein of Jordan wearing an S&W M-19 in an open-top webbing holster of the sort used by tankers for the Enfield .38. The color of the Goncalo alves stocks was pretty... well, pretty! The year was roughly 1970.
If you can find books like, Man-Hunt in Kenya, you'll learn about the early Patchett (later Sterling) SMG's and Browning Hi-Powers used in the battle to contain Mau-Mau terrorists. The paperback I have shows detailed drawings of those. The author was Inspector Ian Henderson, GM. He received the George Medal for his gallantry in working with converted Mau-Mau gang members and turning them against other terrorists. His forces captured the infamous Dedan Kimathi, a murderer many times over, often of his fellow terrorists if he felt they were disloyal.
Sometimes, the make of revolver isn't mentioned, as with, The Brazen Chariots by Major Robert Crisp, DSO, MC, etc. Crisp was a South African cricket star before WWII, in which he served in the Royal Tank Regiment in North Africa and later in Europe, after a lengthy convalescence following severe wounds. It was Crisp who named the US M-3 Stuart tank as the Honey in Commonwealth service. He took one for a test drive and was asked his opinion. "It's a honey!" he exclaimed, and the name stuck. But he just referred to his revolver as a .38. No brand name or model.
On the other hand, Lt. Ian MacHorton named his Colt .38, which he carried with a Thompson SMG in Burma. Look for his, "The Hundred Days of Lt. MacHorton" to read about his ordeal as he escaped the Japanese to return to India.