There are at least a couple ways to do it. The cheaper and probably easier route would be to buy a set of leather seats from a scrapped SVX and install them. Downside to that is you get what you get condition wise. Most leather SVX seats are 20+ years old now and showing it.
The second option which is more money and more work but might come out a lot nicer would be to pick up a new leather kit and have an upholstery shop redo your cloth seats:
http://svx-motorsport-accessories.st....net/inac.html