I have a 20 gauge 101 with M-400 stamped on the barrel. It is a gun that was made for and sold by Sears Roebuck in the U.S. Gun also says Sears Roebuck and Ted Williams on it. But the makers name is not on the right side of the barrel. The Win 101's said Olin Kodensa ( I cannot spell it) on the barrel Almost, but not exactly, identical to the Winchester 101 of the same era. The receiver is not jeweled and there is a slight difference in the forend checkering. The company that made the Win 101 sold to other outlets than just Winchester. I think in violation of their agreement with Winchester sometimes.
Check to see what else the guns says. See if it has Olin K as the makers name. They also sold guns under the Nikko name.
The ceased making guns in the late 80's, I think. My first one was made in 1965 or so.
Anyway I think your gun is a basic 101.
A forum community dedicated to Shotgun owners and enthusiasts including the Remington, Beretta, and Mossberg shotguns brands. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!