Ummm. Ok, if its in the 650,000 to 680,000s, its a first model. Much above 682,000 or so its a 2nd model and the value doubles or more.
Guns sometimes were made with options. K22s are one of those guns that can benefit greatly depending on how it was built.
First, a gun with pitting is pushing the concept of 90% past reason. If its got visible pitting, its lower than that to me.
But a K22 Outdoorsmans revolver with no options is still bringing $600 these days. Sometimes more depending on the region. If you add in a Humpback hammer and prewar magna grips, its above $1000. If its got its original box, it blow up to the $1500 range. If its factory nickel and letters, its at least a $5000 gun.