I looked through the old Star magazine and I think I got my sheepskins either from RamsHead (800-362-6215) or The Great Sheep Co. (516-431-2165). The magazine is so old that there are no websites, but it looks like RamsHead now has a website:
Ramshead manufactures custom sheepskin seatcovers for autos, trucks and airplanes. Sheepskin slippers too.
I think I went with The Great Sheep Co. because they were significantly cheaper. But I cannot find a website for them so I don't know if they are still in business.
Another piece of information that might be useful to you. If your cruise control does not work, don't mess with buying "refurbished" amps from Adsit, etc. They will work for two weeks and then die. Use General Development Laboratories in CA. His website is here:
General Development Laboratories - Home Page
Otherwise, I think there are people on this site who will fix them as a friendly gesture but I used Peter at GDL about a year ago and he was incredibly knowledgeable on the system. I believe him when he says the amp will never fail again.