My 2 cents worth, for what it’s worth!
During the war years, many Whitworth tools were, I believe, ordered directly from the factory by the British Purchasing Commission in New York. They were made to order and I believe some were not regular catalogue items, though many were.
Quality was very high, and I particularly like the WXD 15 degree offset box end wrenches, as well as the deep offset. I have (and use) many examples of both.
Whitworth bolts, up till the war, used a hex size one bigger than BSF, hence some wrenches are dual marked. Most just have the Whit size, since everybody knew this! This is why short wrenches were common, since the bolt heads were bigger!
During and after the war, the same sizes were used for both Whit and BSF. This is why later wrenches are just marked “British Standard”. This is entirely correct.
Some sizes, such as the 1/8 Whit - 3/16 BSF (always a bit obscure) were replaced by bolts with Whit or BSF threadform, but a more common 2 BA hex size. Snap On still make this 3/16 BS wrench, but I don’t think the buyers understand that nothing has been produced in this size since 1939!
