Gary: What you say about the magazine being brittle raises a question in my mind; I know that for legal purposes the receiver is the gun; But what part of a magazine is the magazine? (A silly question in the case of some magazines, I suppose, but anyone who has seen a Calico magazine understands that there are a LOT of parts there!) I do a fair amount of machine work, and replacing the brittle plastic outer case with aluminum or even stainless would be... interesting... But scarcely impossible.
Sic semper tyrannis!