A t-top car would benefit greatly from chassis connectors....all my friends in the US who have used connectors on their T-top cars attest to it.
These same style of connectors were used by National Coach Engineering when they built full convertible 2nd gen cars late in the production run between 79-81.
The ones on my car are so tuff I actually use them as a convenient spot to place jack stands when I was replacing the re axle assembly...nice and solid.
Here you can see the full weight of the car sitting on the connectors....didn't even leave a mark, lol.