The K22 enjoyed a long run, and is an excellent revolver. After 1957 they were given Model numbers. They still hold excellent value today, and I am still looking for one. PoI is correct in the serial number location. While you have the grips off, see if there is a number in them that matches the gun's serial.
Trying to give a DOB based on serial numbers is sometimes difficult. Give a screw count, type of sights and if possible, post a photo. That will help.
Absolute authentication with DOB can be obtained for $30 with a factory letter from Roy Jinks, the S&W Historian.
Try a post on
The S&W Forum as well.
Edited to add....Just saw your last post......
Serial 661XXX falls within the K22 Outdoorsman range of 632132 to 682419. Outdoorsman K22s were made from 1931 to 1940. 19500 Outdoorsman K22s were built. M&Ps also appear in this serial number range, explaining the numerical discrepancy.
Value: NIB $850 Exc $500 VG $300 Good $250. These values from Supica's
Catalog of Smith & Wesson, the S&W collector's Bible. They are at least two years old, and can vary regionally.
Find that box! It's not NIB without the box! Some collectors have paid more for S&W cardboard boxes and screwdrivers than others have paid for guns! The Outdoorsman's screwdriver (it came with the gun for sight adjustment) can sell for $1000! That's right, $1K, no period in there!