I built a Russian underfolder from a beat-up milled kit. It took a bit of careful work to grind the mill-stubs down into "trunnions" using the flat surface area on the side of a grinding wheel. Then I welded them into the stamped receiver (a Coldsteel UF blank). I also had to clean up and refinish the wood a bit. I didn't take any pictures of the build process, because I was winging it, but it came out really nice and it is my favorite AK.