1970 & '71 Gran Coupes had leather & vinyl bucket seat interiors STANDARD.

If you ordered the all vinyl (Gran Coupe specific) or cloth & vinyl, you received a (48.25) CREDIT on your window sticker in '70




If you ordered the all vinyl (Gran Coupe specific) or cloth & vinyl, you received a (44.40) CREDIT on your window sticker in '71


IMO a lesser cost "all vinyl" or "cloth & vinyl" interior is a lesser OPTION in a Gran Coupe, but at this point I don't think they'd affect the value of a finished car. (they do look cool & are considerably "RARER")