I would be interested to know whether it is of a heavier than normal proof. Are the barrels longer than normal? Kirkwood names changed at times. That, together with proof marks, could be a clue to determining approximate date of manufacture. I think Commander Gunther's Gun Report article on the Kirkwoods may tell when the company name changed. I wonder what Don wants to know about wood to metal fit that the sideplate picture didn't tell him? Could there be a clue in that picture?