Tonneau cover doesn't fit!

I have a white (ish) Tonneau that seems too small for my 82 Cabrio. I read somewhere that 79-81 had a bigger roof (when folded) but I suspect my mech is bigger type because this tonneau is close but no cigar.

Is that correct?

If my hood is the bigger type and anyone has an early cover they want to sell or swap for the smaller type then please shout.