No model numbers used before @ 1957. After that, look inside the crane/yoke area.
Standard catalog of Smith and Wesson by supica and nahas
Call Smith and Wesson with the serial number and the will tell you.
Go to Smith and Wesson's website and they will send you one for free.
Smith and Wesson Model No. 2
62092
Standard Catalog of Smith and Wesson, 3rd, edition
You will have to find a copy of The Standard Catalog of Smith and Wesson and check each model number.
Call Smith and Wesson and they will tell you. The Blue Book of Gun Values has some sn data.
In the owner's manual.
Steves's pages
Egunparts
Call S&W