I just noticed this post today while doing a search so here is my input. I've looked into this leather upholstery issue on the zx's and the 80-81 leather was called a leather face kit because the sides and backs of the seats were vinyl. The 82/83 leather/suede interior was on the face of the seats and the sides and back were vinyl however that's when they called it a leather & suede interior because they put the suede on the center section of the door panel like in one of the previous pics. The top was still vinyl, and the bottom section was of course carpet. No leather or suede was used anywhere else.
Nissan made a big innocent boo boo advertising their leather and suede & suede interior and some people decided to get fat on it. The only ones that get fat on those types of issues are the lawyers.
I digress, I seriously doubt that anyone will ever reproduce the leather/suede combo again because it is very cost prohibitive to do the embossed suede. On the bottom face there are what looks like a pair of straps on the face. They are there only for looks, and create a stress on the leather besides being uncomfortable if your wearing thin shorts during the summer. They didn't use the straps on the 80/81 cars. Also the high back seats only came in all vinyl or velour face with vinyl sides and back. The low backs are the only ones that ever came in leather face, or leather/suede face. In the first pic I attached, is a brand new leather face kit with a regular stitch pattern that I have in stock. The customer didn't like the stitch pattern because it didn't match his exactly. The stitch pattern looks more like the vinyl kit stitch pattern which I think looks better than the leather stitch pattern. I'm willing to sell the kit at discounted price of 900.00 + shipping and it's for one kit only. One kit is enough to do both seats. The tan or buckskin leather as I call it costs extra to do compared to black due to the manufacturer of the kits, that's IF they are still interested in doing other colors. they only carry black leather in stock. To reproduce a complete kit with original style stitching for either model of the leather face or the leather/suede face I'd have to have them done custom and the cost would be at least $2500.00 just to give you some price comparisons.
The second pic shows the upper new piece alongside the original worn piece. The 3rd and 4th pics show an original mated pair of leather faced seats out of a 1981 zx with only 80K miles on it. They came out of a car that was totaled hard that we took apart some 13+ years ago, and I still have the seats and they are for sale for 950.00 + shipping. One last note, the original 82/83 velour seats will never be reproduced exactly because of the cost factor. They too were unique to the 280 zx and it's just not cost effective to reproduce them. Z man of Washington