If we use the term 1911 in the strictest sense, then you couldn't walk into the local gun shop and buy one in 1911. As a matter of fact, just about the only way you ever could buy a true 1911 was as a used military surplus gun. This is because M1911 was a military designation, neither Colt nor anybody else ever made M1911 or M1911A1 pistols for anybody but the military.
What you could have bought new in 1911, and still can for that matter, was a Colt Government Model. The Gov't Model was the commercial version of the M1911 and later M1911A1. The Gov't Model was, and still is, available in configurations identical to the military model with the exception of certain markings.
If you want a new Colt Gov't Model that is as close to the military-issue M1911A1 as you can possibly get, then what you're looking for is a Model 01970A1CS.
http://www.coltsmfg.com/Catalog/Colt...%E2%84%A2.aspx