ISO: Tape Seal Belts

I'm looking for a small quantity of 10.5" half-inch reel tape seal belts. These are the things that almost everybody with a large collection of tapes used to hang their half-inch tapes in racks made for the purpose. At one time, like tape write rings, these things were as common as cockroaches. Countless millions manufactured. I can't seem to find anyone who is sitting on a pile of these. Not even eBay. Mind you, I don't want the tapes themselves, just the belts. My issue is that I'm getting sent tapes without cases or belts more frequently. I suspect that in many situations, the belts have just been discarded, as they break and become brittle with age. I can remember discarding the hard plastic cases when refitting tapes for the auto-thread drives. We'd fill up dumpsters with the things. If someone is sitting a pile of the old cases, those would do in a pinch. Any ideas or leads welcome. Thanks, Chuck