I just Aguired a S&W model 65-3 .357 mag SS WITH M.B.T.A. 174 stamped on the frame ,right side below cylinder I'm sure it is Massachusetts Bay Transit Authority police issue was wanting to get history and value if possible! Thank you!
Welcome! With the agency stamping, the chances are good that a letter of authenticity will give you some history on it, namely its ship date and destination:
As far as a value, the condition is the most important factor - figure $400 for a well-worn example, up to perhaps $550 or so for a really nice one. Its law enforcement connection may interest some but generally won't have a great influence on how much it is worth unless someone collects guns from this agency specifically and is willing to pay a premium. Hope this is helpful.