They are not "completely incorrect" for a 1970 T/A Challenger.
The Leather seats were standard on the SE's and an option on T/A's as well as R/T's.
Not too many T/A's got leather interior, but it was available.
You could get away with new leather covers with the correct patteren and keep the carpet on the door panels.
OR
Replace the door panels and get the standard vinyl seat covers and foam.
I would buy a set of core seats and sell the ones currently in the car for a decent buck to help off-set the cost of the new parts.