they just look like the cheap generic aftermarket bumpers that where available in the 1980's
they normally had five holes punched in them, but only three studs fitted (but I have seen them with five studs)
ive seen a few unwary people pay stupid money for new ones on ebay over the years thinking they where genuine n.o.s ones
its very difficult to see the differences in a photo (like it is with s rims and reverse rims!), but the aftermarket ones look a bit more like john majors top lip(

), rather than having the tight, normal shape of a proper bumper.