I think I answered your question over at that other place.
You are talking about a Trooper manufactured after 1962 in 357 caliber (Blue Book says 1961 when the 3-5-7 Mag model was discontinued) and prior to the introduction of the Trooper Mark III. I would offer $400 if it is an original Trooper. I passed on one that was as new in 357 magnum that the seller was asking a firm $650 with pachmayr stocks. I offered $500 on that one.