I believe you can convert the 70 seat to the 69 style seatback release latches. I have never done it but I did look at a 70 seat with the cover off and I believe it had a cable down to the seatback release. I think you could remove the cable and replace the seatback release with the 69 style, which by the way can be found on a dodge pickup with a king cab and a bench seat that leans forward for entry into the back.
Jess