I posted a thread about this case before but never got a satisfactory answer. Anything over 20mm seems to be a real pain to identify. Shown below is an exact copy of the headstamp, drawn by hand.
Can anyone tell me the manufacturer of this case, I used to think the maker’s mark was the “LH” on the right, but now also think the “K N” near to the primer could perhaps be Kings Norton Metal Co.? To confuse matters further the “N” above 1940 could indicate naval use. The 2 markings in the to left segment look like a poorly stamped “F” and a very poorly stamped “B3” or possibly “D3” can anyone shed any more light on the manufacturer and which service used this case? I have no idea about the primer, which appears to be made in 1942. It could well not be original, as it is loose and can be unscrewed by hand. The case has been highly polished on the walls, but surprisingly the head looks to have never been polished, showing original annealing colours around the primer thread. The turning marks on the head are also very clear.