The next time you take that excellent hard hard top off would it be worth placing a long piece of card along the new Lower edge and tracing the outline to form a template ? Or is the general feeling that the 507 panels don't fit consistently enough for others to use the same template?
I don't think anyone could, or should, use a template made from my car.
Each car is slightly different. Each one is installed different too. I think my rear panel is mounted a bit high in the front/middle. The left isn't the the same shape as the right.
Tribute did make me an extra sheet of grp moulded around the front of the rear deck but I couldn't use it as intended but it certainly helped, a lot, as a guide and as material to fill the gaps.The roof needs so much cutting off that it's no longer directly above the body and it's just a case adding and removing material by eye. The roof is also double skinned with a metal bracket for the rubber seal. All that has to be chopped off. If you have a hardtop you'll know what I mean.
For a lot of the work I had the roof suspended over the car as I was working.
Don't want to put you off. It's a lot of work but I think it's worth it.