This is my first time posting here but I figured some of the non-machinists may be interested in the story behind the simplicity of a Polymer80 build. Using just a cheap Chinese dremel, cordless drill, and some hand files, I have a reliable Glock 19 style gun built from Gen 3 parts. Biggest complaint is that not all the drill holes matched up perfectly, so I had to widen them a bit to get the Glock parts to fit.
It does well with my Liberty Mystic X and fits in crossbreed g19 holsters for carry. I hadn't seen much info on holsters online, but I went to my LGS and was permitted to try just about everything. I had the best luck with crossbreed's freedom line, and found that it didn't fit in blackpoint tactical or galco. It also works in the glockstore $35 holster, although it's a poor holster for concealed carry. Let me know if anyone has questions.