Yes that is a 100% factory correct appearing set-up ! You could get orange/black material with black vinyl as shown in the picture in 1971 B Bodies, etc..., and as far as E Bodies are concerned it was available in the 1971 Dodge Challenger only, but more of a orange plaid then houndstooth.
I agree that the seats you pictured are possibly custom made because they appear to be a 1970 Plymouth Barracuda seat pattern which were never available with that combination.