
That said, the butt plate of that era should be a walnut colored bakelite butt plate, much like this one off my Godfather's early Model 870 20-gauge --

However, to really pick some nits, underneath the word Remington it should say in tiny letters "REG. U.S.A. PAT. OFF." while this 1951 vintage plate has "REG. U.S. PAT. OFF."