Jonathan,
A lock that would be worth recreating with the stock you have salvaged would be a
Montenyard lock. I am not 100% up on my 20th century US foriegn policy history but the notion I have is that one of the greatest allies y'all had in S.E asia were hunters who used locally forged side locks. A member on here reported his experience seeing them in the field 50 years ago +/-and had high esteeem for them.
To most eyes they are crude and 'foriegn'- really though they are the ultimate symbol of the fight against socialist oppression. Imagine a friend who you could trust to go up against an SKS toting commie with a monkey gun!
I am optimistic but even so I bet you could make one that would fire reliabley in a weekend. Be a great first lock and a chance to sort out the working/tempering properties of the salvaged tool steel you got from work.