This is the 3M 08008 stuff I used on my 72 T-Top, when I bought a full weather seal kit from a seller in US.
I purchased the adhesive from the UK Mustang Club! Pretty good price, compared to all other suppliers on Fleabay etc.
Did all the door seals, T-Tops, rear window and bonnet with a tube, with spare left over. Has bonded really well, did tape both door seals in place for an hour or so, then closed doors, bonnet, rear window and T-Tops were left for an hour, then closed to seal/compress. So far so good when out and about and having been caught in a few showers, even when parked up.