REAL Speedsters (Porsche) had a steel top bow with a rubber insert. The top would be glued to the top bow, not the rubber. Replica cars have a fiberglass bow. The installation is about the same. The rubber goes in after the top is glued in pace.
I can't imagine anyone trying to hot glue a top on! I have installed several tops. If you're not able to do that you'll need a good top shop.
Most of us have Hartz canvas tops...I believe.
Look for Alan Merklin. I suspect he's installed more Speedster tops than anyone else here.