Drew and Toby, those are nice clear marks. My example is a very small mark best viewed in a good light with a magnifying glass!
Had a look at a book I have that is a biography of Sir Joseph Whitworth by Norman Atkinson. Had a good but quick look through but only found reference to the fact that he was supplying guns for the American Civil War as the earliest reference. I tried to find reference to the use of the 'Wheatsheaf' Trade Mark but without success.
Another book I have on him; 'Joseph Whitworth. Toolmaker' by Terence Kilburn lists his patents. Patent No.3062 of 1874 for Compressing fluid metal may refer to his sporting gun barrel steel. He has one for Breech loading firearms and cartridges; Patent No. 963 of 1867. He was by all accounts a Mechanical Genius but a right old misery and a tyrant with his workforce. Lagopus…..
