In addition to Post 2, the dash number (i.e. Mod 60-1,2,3,4,5,6,7) will then provide some other engineering info or differences about the specific model which someone will be able to share.
Get on Gun Broker. Sign in. Then go "advanced" and search "completed auctions" for "S&W Model 60." Pay attention to the auctions ending with a "sold." That will give you a ballpark value idea.