Here's a few of a dozen sites that talk about what to look for:
We get 1911's in everyday that are parts guns, they usually retail in the $300.00 range - plus or minus. No real colletor value other than for parts that may be used to make another 1911 closer to a same parts manufacturer gun.
NRA/NMLRA Life Member
Basic Rifle, Pistol, Shotgun
Basic Muzzleloading Rifle, Pistol, Shotgun