One of my brothers once owned one of these six-inch British-shipped guns. They're around, if not as common as the five-inchers. Many with four inch barrels were sent to South Africa, which is what Digi-Shots was probing for. (She is a superb photographer with an interest in the South African shipments.)
As an aside, my brother decided to dry-fire his one night when I wasn't home. He was still a teen then...He forgot to unload, and put a 146 grain lead bullet into a thick book lying flat on one of my bookcases. It penetrated only about an inch, which didn't leave an impression of great power. The book was hit near the spine, on the bottom edge as it lay flat, the end facing him at eye level. I hope the bullet penetrates better in flesh than it does in dense, slick paper! Probably does.
I saw a wartime photo of RAF personnel in formation, wearing these six-inch guns in North Africa. They had the usual Pattern 37 webbing holsters, made for guns with five-inch barrels. The butts stuck WAY out, and the longer guns probably stretched the holster flaps. I'm surprised that the flaps would even snap shut.
The finish appears to be a commercial blue, although I agree with Lee that prewar commercial guns were more brightly polished. However, the one that my brother had was in NRA Excellent condition, and the finish was definitely brighter than on some commercial M&P's made in the 1940's and '50's. Those were actually dull in comparison, little better than on the M-28. Indeed, I have seen individual M-28's that had a brighter blue than was on some postwar M&P's.
Oh: RAF holsters were usually grey, Army holsters were sort of olive green. I think the Royal Navy used mainly white holsters, and some Army MP's also had white ones. However, those were probably for headquarters duty and for parades.
I have also seen one of these six-inch guns on the desk of some Army sergeant. He was in some headquarters or communications office. Not all of those longer barrels were RAF-issued.
