Dipped in oil based in stain. Drip dried. Sprayed with Duco(Dupont Company)lacquer. Lacquer was not very glossy back then either. Ended up between satin and semi-gloss. They get glossier with handling over the years.
This was explained to my by a man who worked at Winchester in the 50's.
I think the mysterious finish was from the era preceding the 30's.
