I have to agree, not sure a T-top woudl fly well on a first gen, but pretty sure it can be done. you can mock up some black vinyl in place to get an idea on what it woudl look like.
I would try something different instead, and had it in mind if I were to "build" a removable hardtop bird. I have found a few pics online of a convertible Camaro first gen, and the guy built a removable hard top for it. All in all, not really a bad idea, and seems could be done somewhat easily as you can buy sectins of teh quarter and roof. Kep in mind windshield height, angles etc woudl be something to think about it. I think if I com across a wrecked bird, I may be interested in a chopped roof to play with for kicks
Gui