Check ipdb.org as I believe the photos for any of the games there are supposed to be of original format games with no mods etc. There may be a photo that can give you clues. The holes look like they are for posts and maybe the ones originally used are the wood screw type and those you have are the larger ones that take a nut at the other end. What style is from your original pf? Does manual refer to any type of post at all?
