Hello
Here are some noteable Mentions with some very different design changes.
A First series K-22 Outdoorsman that shipped in September of 1936 shown with it's box & Original Serial numbered service stocks
Here is a November 1947 K-22. This one is a Transitional K-22 due to it's Larger Mushroom shaped extractor knob of Pre-War style S&W had to Mill out the under side of the Post-War barrel to allow the Extractor Knob end to clear the barrel portion when the cylinder was closed. S&W was not a company to waste parts if they could be used that is why we see these Rather Scarse Trasitional models like this one shown with added on Target stocks, it's box, Tools and Paperwork. I have the original serial numbered Magnas it came out of the factory with stored away.
A Pre-17. This one had a very short production span as a Four Screw variation being non Model stamped. In Late 1955 they dropped the upper side plate screw, and in 1957 they started stamping all guns with a model number as the K-22 was given the model number 17, leaving This Variation a very short window of production falling in between Early to Early 1957 time span being less than A year shown with it's original Box, Tools, Paperwork, and Magna serial numbered stock's as well as it's original sales reciept from 1956 as it was shipped and sold through a huge S&W stocking whole sale dealer being the Shapleigh Hardware company of St. Louis MO.
Here is the K-22 Magnum. This is a First year Model 48 that shipped in December 1959 being the first year as well for the new Exciting Winchester .22 W.M.R. Cartridge. It is a Four screw variation in Bright blue shown with It's Factory fitted Optional .22 L.R. Cylinder along side it. S&W Offered these with both cylinder's for awhile at a small additional cost to the buyer, but they are no longer made up or offered this way.