There is nothing in the Chevy lineup that is worth as much as an original Cobra (except for a couple of really special Corvettes). Therefore, most collectors would buy an original rather than a "replica" Chevy.
From a manufacturers standpoint, the only vehicle that I see that could be a money maker as a replica would be a 57 Chevy Convertible.
and to think that I sold one in the mid-60's for $350.00 