Colonial Chairs

I have  4 Colonial S.Bent & Bros. Ladderback chairs. I have 2 captian chiars and 2 regular dining chairs. They are dark brown, but I'm not sure what kind of wood they are made with. They are in very good condition accept 1 of the captain chairs has a slight worn spot on the seat. The S.Bent  & Bros. label is carved on the bottom of all 4. The #'s 851  1074, and 852  0974 are also carved on the bottom of the chairs. I don't know anyhting more about these, because the man we bought our house from had left them along with a large drop leaf table that goes with the chairs.