Gotcha,I have about 12 of them.
I have barrels & the "paperweights" but nothing else. As you stated there looks to be a bunch of machine work to do. Looks to me like they have about 20% done and 80% left to go!Gotcha,
I have inspected them, and if you have what the same receivers that I have seen, then there are quite a few difficult machining operations left to do. Just cutting the slot for the charging handle will require a fair amount of setup and work. Not bad if you are doing it yourself, but if you are paying a machinist, well I would hate to see that charge. Pretty sure the barrel threads needed to be cut, and the threads aboive the barrel for the piston tube nut. I remember those receivers looking like they needed quite a bit of finish machining, almost all of the surfaces looked to be oversize to some degree.
You could buy a complete dsa receiver and start measuring, see what is in spec and what needs work. Do you have 12 fal kits to go with those paperweights?