Winchester model 12-20 gauge standard trap|Winchester Shotguns|Forum|Winchester Collector

Came across a model 12 thats stamped “Standard Trap”. Its a 20 gauge thats in almost mint condition. I have seen 12 gauges but this is the first 20 gauge that I have seen. The serial number is in the late 600000 range and the barrel is nickel steel with a 28 inch solid rib. Some books say 1933 was the last of the nickel steel barrels but I took a flashlight and the barrel is marked 35 underneath. It also says Full. The receiver also dates to 1935 as well. The catalogs I have say they came with a pad but this gun has the plastic buttplate. It also has a uncapped pistol grip and the small forend with the checkering pattern the same thats on my 1922 Black Diamond trap(12 gauge) The wood is beautiful and rivals some of my higher grade winchesters. Does anybody else have a 20 standard trap in this era? I figure this gun was special ordered and being a 20 gauge- Im guessing its a pretty scarce gun. Just trying to figure out what it is before purchasing.