Almost all sealant on these cars was butyl as opposed to the urethane used now. Be aware that the two are not compatible. Butyl sealant tape is readily available online as well as at RV supply houses. It generally comes in either white or black, although I have seen grey. It is easy to apply and doesn't leave a mess (usually), just stretch to fit, then press in place.
I've used it for the front and rear window trim and never had a leak.
Hope this helps
Terry
64HT
Drip rail and vinyl top
Moderator: redstangbob