No way to answer without the serial number.
Made in 1951
it's a pistol............
It should have the caliber marked on the barrel,such as"38 Colt New Police".
32 caliber is a little smaller then the 38 caliber
manufacured about 1915.....................
made about 1917
Without the serial number and a very good description to include caliber, bbl length, all markings and any accessories, the question can't be answered.
made about 1919
Assuming it is a Police Positive Target if it is .22 caliber. It all depends on condition and exact model (1st Issue, 2nd Issue). Anywhere from $200 to $700 plus. firstname.lastname@example.org