Well I took a big chance and got these seat covers for my 6C.

1975 1978 Jaguar XJ6 C XJ12 C Coupe Leather Seats Cover Custom Interior Front | eBay

The patterns were correct for my car, as most cheaper covers advertised are the narrow pleat versions. But I need seat foams, front and rear. Can't seem to find a source, can anyone help?
Bill

1975 XJ8c

 

http://www.aldridge.co.uk/services/schematic.cfm?id=3

 

Hey thanks Brett. Any ideas on the rear seat foam? Mine has a full molded latex foam cushion on top of the springs.

 

I made it also new...just remove the old stuff and glue a complete layer of 5or 6cm thick foam on the canvas ..the rest will do the leather cover