Hi, Max, are you sure that the T-Rex, Triceratops and Pteranodon from Polar Lights are not new moldings of the original Aurora designs? I built the Aurora prehistoric series when I was a kid, all except the T-Rex, and the Polar Lights models look like the same models.
The Triceratops was cast in blue plastic, the T-Rex in an orangish or goldish red, the Pteranodon in orange. It had an optional "battle scarred" wing, and its feet were cast just as in the picture posted above of the current Revell molding.
Those were great kits, if they weren't too accurate, based on current paleontology. But with the interlocking bases, you could put together a big diorama of prehistory. Of course, I played with those models, and they all succumbed eventually in adventures with GI Joe ("GI Joe and the Wooly Mammoth", "GI Joe and the Lost World", etc.)
Anyway, the Pteranodon could serve as the basis for a decent-enough kitbash.
Happy modeling!
Brad