51 Colt Model Police Positive "First Issue" in 32-20 WCF with 4" Barrel - Man. 1919. This revolver is the improved "positive lock" version of the New Police and it features hard rubber grips, square butt, a smooth top strap and a deep blued finish. The gun is in excellent condition and is quite collectable. Serial #: 162966. Estimated Value: Low: $1,000 High: $1,200