4 Brown w/ Tan Plastic Vintage Round Buttons 4 Holes

Set of 4 vintage brown with tan marbling and 4 holes. I'm pretty sure these are plastic, but the backs sort of feel like wood. They are a molded one-piece. Each button is 1 1/8 inch diameter with a 3/16 inch thickness.

There is one that seems a little darker than the other 3 and the back has a ring and the other 3 do not. See Pictures.

Buttons 1-19