This could be a one of. First of all it is a .22 caliber. Secondly, and most importantly, it was Fitz'd at the factory. J. Henry Fitz-Gerald worked for Colt from 1918-1944. His resume' is very impressive. He was a firearms expert. He testified in almost 1500 trials where firearms were used. He was also a consultant and lecturer for many businesses and police agencies. The Fitz-Gerald alterations usually included shortened barrels, a cut trigger guard, bobbed hammer, and shortened extractor. This pistol has only the cut trigger guard and is verified by a Colt factory letter. This Colt pistol was shipped, on loan, to Lieutenant Robert (R.M.) Bair. He was a pistol instructor with the Pennsylvania State Police. Mr. Bair is also the author of "Manual of Police Revolver Instruction" written in 1932. At some point he found time to be mayor of Hummelstown, Pa. When looking at the pictures, be sure and notice the verified proof mark on the right rear of the trigger guard. Normally this mark is found on the left front of the trigger guard.
Officer's Model Match. It shipped in 1962 to the Royal Oak Police Department, Royal Oak, Michigan. R.O.P.D. is engraved on the butt and verified by the Colt Archives letter. It is a single action only which is fairly rare and also verified by the letter. I don't recognize the stocks.