Thanks! It has "RODGERS SHEFFIELD ENGLAND" on one side and "27C/2360 arrow" on the other. The latter being the RAF stores code.
Early models (pre NATO codes) are marked
1B (RAF and army small hand tools category)
22C or 27C (RAF survival Item)
0274 (Royal Navy "Tools, General")
Later they just had the code 5110-99-127-8214 with or without makers mark or date.
According to Flooks excellent book on Commonwealth military knives the cheaper and nastier versions with the rivetted on grips came out in the mid to late 1970s.
I think a lot of the bad press the type D gets is due to the poor quality of the later versions so, if you can, pick up a early one, most readily identified by the bolt on rather than riveted scales rather than a current issue one. The things are so robustly made that even a heavily used one will clean up very well, mine did.
Perhaps I should dig out the block of curly birch I got off Ragnar years ago and make some prettier scales for it? The bolts look to identical to those on the 1907 Pattern bayonet, minty new ones being available from people like D.S. Solutions.
ATB
Tom