I finally got around to throwing a parts kit (DPMS)and buttstock onto a stripped lower (RRA) for the first time yesterday. Total time was 55 minutes not counting tool roundup and work area setup/takedown.
I had always read that installing the bolt catch rollpin was the best opportunity to scratch up the receiver. I covered all vulnerable areas of the receiver with duct tape. My 3/32" rollpin punch doesn't have the sleeve to hold the pin when starting it. Instead, I cut about 1/2" off the end of a stick pen cartridge (no ink), chewed on it a bit to soften it up (I know - gross) and then put the rollpin in one end and the punch in the other. This way there is just enough flex so you can get the drive end of the punch above the rear receiver ring where the ext. tube screws in, but is still straight enough to easily drive the pin through the 2 holes and the bolt catch. Worked very slick and no damage to the receiver.
I used the clevis pin trick for the front pivot pin. The thing that took the longest was driving the rollpin through the front triggerguard strap holes. Very slow going.
Everything seems to be working properly mechanically. If it doesn't rain again today, I'll try and get it to the range