I'm still using 2 that I put away some 35-40 years ago. My favorite is this stuff that comes in blue tubes that say Mastice Gutta, and nothing else. Unfortunately that simply means Gum Mastic in Italian. It's very nice with good adhesion even when tires are mounted wet. Plus it has lots of solids so it makes an excellent bed, filling and matching the curvature of the rim to the tire. By the third tire, I have a great bed. It stays tacky for about a year, so I can mount tires on the road without fresh glue and ride immediately.

Once I have a good bed, I use Clement cement form the same era. It's the old brown stuff which also has excellent wet adhesion, and the ability to remount a new tire without fresh glue. Even though this is great stuff, I only use it because I don't want to use up the other stuff.

The other excellent glue from back then was Continental which came in a golden can. It had the consistency of shoemakers glue and was a stringy mess to use, but like my Italian stuff stayed tacky for a long time, allowing road mounts without glue.

With any luck I have enough left to outlast me. Otherwise I'll go to some kind of weatherstrip cement. I used to have good luck with Fasttack, but quit because it was too good and the bast tapes would come off when I pulled tires.

I don't know what's out there today, but many products of the eighties were a fail. They lacked 2 key requirements; enough solids to make a good bed, and staying tacky so reuse on the road was safe and reliable for up to a year or so. Glus that dry dry are useless except for the track, though riders racing with support can use them since they won't be changing tires on the road.