I have a K frame from 1958, no model number on the frame, and it for sure chambers 357. It is blue with 4" barrel and adjustable sights, the ejector rod is not shrouded. Barrel is marked 38 S&W, serial number is K3300XX. The frame behind the crane is marked with an M and a 3 within a circle and what I believe to be a 4 (may be a triangle) below that, and there is an M on the left side of the grip frame. The crane has an assembly number which matches the one on the grip frame, and it also has a T and I think what is the number 5 on it. If it's a 1958, and S&W customer service says it is, shouldn't it have a model number? It seems I recall reading some police departments had them re-chambered for 357, can anyone verify that? As I said it does not have a model number on the frame, and it is definitely chambered for 357. The cylinder measures 1.56", it looks like a model 15. Not sure what I have but the action is incredible and shoots like a dream, I don't have any way to provide any detailed photos. I don't have any intention to use 357 in it, I have other 357's.