Little update, first thanks guys for the info so far, I’m defiantly going to get the books, got one this week.I am very fortunate to have the resources to build just about anything I need for the gun, so I’m starting with the right side plate, I found a cad drawing on the internet , put it in our cam , assigned some tools and bingo I have a CNC program, found a piece of 4140 , now I just need to wait for a open machine to make it. Incidentally I checked the hardness in a small piece of the original side plate and it’s mild steal maybe 1018 or so, so 4130 is not necessary , but will machine nice. My question for the day RIVETING,, I’ve built a few AK- 47/74’s and used a hyd. Press to set them, I see some YouTube vids of guys heating them and then using a pneumatic hammer on them is this a acceptable way ? We do have one of those air over hydraulic rivet squeezers but I don’t know if it will fit into the box. What is the best way to set the rivets ?? Thanks. Jon P