I might suggest if you are going to all the trouble to buy a base model 1911-A1 and then strip it and throw away the "spare" parts,...just go to Brownell's or Midway's home page and see what a "matched" frame and slide cost. Maybe a Caspian or even a STI or something like that. It will be totally custom as you have selected the parts.

It can be, but generally these parts are slightly oversized to be fitted, by a competent gunsmith for a nice tight fit. Which is the reason for my earlier suggestion. If you have to visit/pay a gunsmith anyway, might as well drop off a bag of parts and have your gun fitted together with the parts you want the first time.