older vacs is that they tend to use disposable bags

Yes. I have emptied many disposable bags and kept on using them. Takes five or ten minutes and is a filthy job (don’t rip it!), but quicker than chasing down more bags.

I’ll bet you could use some type of modern sealant to make a “rubber” gasket. Spooge it out onto a glass or stainless surface, shape it and let it dry. Trim to fit and viola. Bob’s your auntie.

In light of the hard times coming down the pike, we’ll all need to be more resourceful with mending and maintaining all the products that were planned to be scrap after one year (or warranty expiration).

Edit: I would also add that if this gasket touches food or food surfaces, do not use just anything that might transfer toxic elements. Also, I hang on to all sorts of stuff and have a stash of rubber bits I toss into a bin. Something could be made from that as well. My pack-rat ways are going to finally pay off. ;(