Soft Corinthian Leather or is it Vinyl?

I scored a set of leather seats for my 76 Cordoba. They are out of another 76 a guy is parting out. They are in decent shape, but will need to be redyed. I was wondering though if my suspicions are correct in assuming that the leather is only the inserts on the seat and the seatbacks of the seats, and not the trim portions or head rest areas. Is that correct? I want to make sure I prep them correctly and don't want to mess up either the leather or vinyl by using the wrong cleaners and prep materials. As always, any input is appreciated.