What does this stamp indicate please.

[Brian Dick]

I have a little 152 page book available called: "C.O.C. Training Centre, A.21 Lecture Precis No. 46/ Extracts from Instructions for Armourers, Revised Feb. 1943" that has a whole chapter titled "Browning Mixture and Process". It's basically a rust bluing process. This is a wonderful book that covers weapons, accessories, tools, and even bicycles. A bargain @ $20 plus post. Every swinging dick who wants to work on British and Commonwealth weapons from the WW1 and early WWII era ought to have one. I won't be printing anymore so get one now while you can.