I'm now pretty confident that my revolver was manufactured in 1937 on an Official Police frame. Just the trigger guard shape is all wrong for a 1950s Police Positive Special.
EDIT: I posted the previous information last night. Then I looked at your photos once more today, and realized that your guns serial number is shown in the 3d photo, and its not a 6 digit number at all, but a 4 digit number. Its the number shown inside the open crane. It looks to my old eyes like that serial number begins with an 8 too, instead of a 6, but that could just be my eyes playing tricks or the photo playing tricks.
Photoshop is a wonderful thing. I made the last 2 digits disappear but there are six digits and they begin 6210__.
My daughter isn't computer savy in the normal sense (like trouble-shooting a network problem, for example) but she's hell on wheels with PhotoShop. "I don't like those people in the background so I'll just make them disappear!" Got an ugly telephone pole & wire in the photo? NO PROBLEM! Blending out a couple of digits against a dark background is child's play.
You can't trust any electronic image today.