My 1925 Star Touring has a hole in the wood at the top corners of the rear seats like the pictures show. You can feel it by running you finger along the upholstery. Unfortunately, the wood was so old it cracked when I lowered the top into the saddle.
Many years ago we had some of these recast using mine as patterns.
i sold sets to owners of cars other than Durants and Stars
they are probably "universal" to many different makes