is the 67-69 camaro back seat the same as a 68 -72 nova?

No...

The camaro rear seat is not as wide as the Nova rear seat. I actually have a rear seat out of a 68 Firebird (in addition to my stock rear nova seat) and am looking into a way to make it work in the back. The Camaro's and Firebirds had special rear panels that had arm rests and ash trays and I'm trying to mock them up using a Nova door panel and see how it all fits. I think it would look cool, but I'm not sure if it is going to require additional filler or not.