.45 ACP means Automatic Colt Pistol. It IS .45 Auto.
.45 ACP means auto cartridge pistol ( I believe they spelled it pistole though). The .45 auto just means it is an autoloading pistol unlike the revolver style pistol.
100-400 or so
ACP means Automatic Colt Pistol. .45 ACP and .45 Auto are the same cartridge. .45 Colt and .45 Auto Rim are a revolver cartridge. .45 GAP (Glock Auto Pistol) is a shorter round than the ACP, and does not interchange with it.
Yes
No. The 45 ACP (which means 45 Auto) cannot use the .45 GAP or the .45 Magnum.
Best left to a gunsmith
Colt has never made a 45/410 pistol
300 USd
To vague a description. Could be worth 500-5000.
100-1000 depending on specifics
Automatic Colt Pistol. Colt invented the .45 Auto and thus had the right to name it.