1980's (+/-) 60/40 seat with Nomad material sewn to give it the correct appearance. I noticed this one on ebay - think that maybe it's at the shop of Greg's 56 Nomad...? If so he might be able to I.D. the seat. I've had a couple of 50/50 seats from certain Lincoln/Mercury 2-dr coupes/sedans, and one from a Mopar of some sort...that one was a little too thin like the one in the picture. If you're going to make that kind of a modification you need to consider the over-all width so it looks right. The Lincoln/Merc ones I had used are hard to find now, but sure were comfy. Would do it again if I could find one.
JR