The Corvair was a '67 minus stock wheel covers. No side markers, '67 interior, all '67. The Camaro was a '67 with trim removed from the body, modified grille, and custom interior. Still had vent panes on the doors, and no side markers. '67 Rally wheels and '67 taillights. The Camaro got reissued as a "for '68" Firebird; same interior pattern, custom grille, and a rear bumper out of someone's imagination.
The '67 Impala became the "for 1968" "Chevrolet SS 427". Trim removed (including windshield wipers), no stock bumpers, hood bulge smoothed off, and rear window completely filled in (don't know what they were thinking with that one). AMT was issuing some kits for Mexico with Spanish-language boxes in this time frame; instead of selling the "for 1968 Chevrolet SS" there, they dusted off the '66 Impala instead.
--Mark