1970 Deluxe Highback seats

I want to put some Mach 1 seats in my 'Stang but they're so hard to find. When I do find them they're pretty expensive and usually need recovering. I was wondering if the 1970 seat frames are compatible with 1969 or 1970 Mach 1 foam and seat covers? Is the seat release handle in a different position and does it matter? It could be that the cut needed to clear the handle is not in the covers yet and can be added as or where needed?  

I have a perfect set of 1969-1970 Mach 1 black deluxe high backs with a red stripe that I would be willing trade for a perfect set of 1966 fastback low backs with black crinkle vinyl. I'm restoring a gt350 and need the badly.  

I believe the two are compatable. If not mistaken, the only difference is that the '69 seat backs had a red stripe and '70 was grey. Good luck...  

The seat bolt paterns are the same for 67/70. The high back area can be removed from a 69-70 high back seat and spot welded onto a 67-68 seat back assy, if that top is removed (man was I happy, give me a pair of rusted seats!). The last seats I reupholsted, I reused the standered seat (high back) foam, with a Mach 1 kit from Mustang Unlimited, they looked great. The 65 may/can have the 70 seat installed. You can place a piece of flat stock across the 71-73 seat bottoms frame and with the tracks from a 65, then install it into a 65-66. Without seat or rails mods. The mustang Mach 1 had several stripe colors in the seat back. 70 was the 1st to have high back as a standerd seat, not just Mach 1's.