For sale is some nice used rubber from a Euro station wagon W123
Generally quite good condition, hasn't dried out like you see sometimes, still smooth, no cracks along the edges where the bumper slides in like you often see.
The only real flaw I've found, beyond the unavoidable age of the part, is that one of the holes for the bolts that help secure it underneath is cracked. The other three are just fine. The bumper rubber was still secure on this car despite that, and it could probably be easily fixed with some epoxy. It's also out of sight when installed, so it doesn't affect the cosmetics.
I put on a light coat of Gummi Pfledge, a few more would bring back even more of the shine.
Looking to get $75 + shipping. Shipping shouldn't be too bad. The parts are a bit bulky but quite light. PM me or post here if you're interested, and share you zip code for a shipping quote.