K-22 Nickel Question

[papalondog]

Found a model 48 in Nickel finish. I know they are not a catalogued gun. Do all of the special order nickel finished guns stamped with an “N” on the grip frame? I have reason to believe this is a factory gun but there is no “N” stamping. Serial number 6K2407. HELP!

 

[s&wchad]

A photo of the left side of the grip frame may help. Also look on the back of the cylinder, under the extractor star.