It depends on the model. Mossberg used a few different finishes over the years. Some were stained with a reddish tint and oiled, others had a type of varnish put over them. You almost need to be model specific. I know over on rimfire central, Mossberg finishes comes up quite often for discussion. You might want to check with the guys over there on the Mossberg forum. They will tell you all you want to know about the older Mossbergs.