I ain't gonna say nothing about "the guy who...". I've seen baaaad things, man. Guess I did kinda write a eulogy for a roof skin. Anyway, no on the ratchet strap and block of wood. Why would you need that? Clamps then screws where welds were should do for positioning the new panel.
I have never put a roof skin on a 2nd gen F-body
, but have replaced a variety of roof skins in my time. Again, the last one I did was DC and wonderful. While you wait for delivery, I suggest a thorough search of the web for a detailed roof replacement article on a Firebird just like yours. Surely theres something out there