Hello. I am needing help identifying my father-in-laws S&W .38
The gun is nickel-plated (I guess) with wooden handles. I found a number on the bottom of the frame (between the grips) 357636. That same number is also on the bottom of the frame below the barrel. There is also a number on the inside of the frame where the cylinder swings out 61211.

Any help in identifying when this gun was made, etc. would be greatly appreciated.

Thank you