Colt Police Positive Target .22

Several years ago I found this Colt .22 Police Positive Target revolver in the used guns section of a police supply and gun store. It was in very good condition and stamped on the side-plate was U.S. Customs. On the butt was No. 2209 which I presume was put on by the agency as the serial number is 455XX making its year of production 1941. I'm not sure if it was used to train Customs Inspectors/Agents or was used by the agency pistol team. I have seen pictures from the 1930-40's with them in the hands of Treasury Dept. Pistol Team members like Lee Echols (author of Dead Aim) who was a Customs agent. I talked with Echols in 1992 and got his other book "Hilarious Hijinks & Dangerous Assignments," but did not have this gun at the time. Can anybody out there shed any light on this fine revolver? Also if anyone knows what the status is on Lee Echols, I'd be interested in knowing that too. I beleive a little Colt like this one was also featured in a Skeeter Skelton story, back when he worked for Customs.