Wasn’t there some where in Texas you could go and make your own personal lower receiver?
IIRC, there's a TechShop near Austin now. That's a membership-only place, though, but they do advertise having a 4-axis CNC mill.
There might be a policy against gun work there, too - you should probably check. It might be cheaper to buy an "80%" receiver and the required drill jigs and other related bits and tools, and a cheap tabletop milling machine from Harbor Freight.
You can order an 80% complete lower and then finish it yourself with a bench top drill press and a jig.