Hi Rob, I don't have copy of the 1931 Instructions for Armourers so I can't really answer the question. I'm thinking it's a bit of a condensed version as it clearly states on page 5,: (For issue to Armourer Trainees during a scarcity of the book. Not a replacement. Not to be quoted as an authority.) If you want to email me direct to
bdlltd@bellsouth.net, I'll be happy to scan the table of contents. I've learned many weapons with this book at hand. My copy in the work shop is covered in greasy fingerprints. I met a gentleman in Kincardine, Ontario in order to borrow an original, (which was returned), for reprinting many years ago.