Great resource for gunsmiths
If you want a great resource for any gunsmithing or small metalworking projects then Brownell's "Gunsmiths Kinks" Vol 1-5
If it isnt in one of these then it hasnt been done.
Everything from removing small screws through blueing and browning, nickel plating, stock making, checkering etc etc. Hundreds of useful practical hints sent in by gunsmiths over a 50 or 60 year period.
"Entia non sunt multiplicanda praeter necessitatem"