I got a supressor that looks like the bottom one in your photo on an Egyptian FN49 I bought. Can't tell if it's identical without the dimensions, but it is the same configuration. From what I've read, if it's for an FN49 it's an aftermarket product, because the Egyptians didn't use any kind of suppressor or muzzle brake on their rifles and FN did't make any in that configuration. Unless, of course, it's an original for some other weapon that was altered or just happened to fit an FN49. It ain't much, but that's what I know.
--DJ