I am FAR from an expert on Winchester trench guns however I have read alot about them. From all that I have read, all 97's and 12's were originally blued and were parkerized in an after war rebuild program. Again I am no expert but have never encountered any imformation about factory parkerized. May I ask you where you obtained your imformation?Initially the M12 Trench Gun came in both the blued and parkerized finishes. The blued ones were in the 980,000 to 1,029,000 range and the parkerized ones in the 1,030,000 to 1,040,000 range. I have seen several M12 Trench Guns that were originally blued but are now sporting a parkerized finish.
I stand corrected. Guess I need to go back and read again. Thanks.Except for some of the Vietnam era shotguns, the only orginal factory parkerized US Military contract shotguns were the late made WW2 Winchester Model 12 trench guns. Every other riot or trench gun made during WW1 and WW2 had a factory blue finish. So, except for those late made WW2 Model 12 trench guns, any WW1 or WW2 made riot or trench gun that is parkerized has been refinished either during rebuild or privately.
Thanks I will check out his book. I have seen a few errors in his book in the past but most times he was very accurate with his imformation. For what its worth I have a WWII Stevens trench gun that is blued.My source of information was, "Blue Book of Gun Values" by S.P. Fjestad, 14th Edition, Page 951.
I have exploded diagrams for the Stevens 520 which may be of some help. I can copy what I have and send to you. Be aware that the different models, -20, -30 have different internal configurations so parts for the -20 will not work in the -30 adn vice versa.Now comes the hard part. The damn thing's got more little parts than a Xerox machine.