Do searches (on this site) for SL convertible top lots of information; you can even find covers on eBay.

Performance Auto of California is extremely expensive.

http://www.***************/ for parts

http://www.eris-car.de/ for interiors

http://www.prestigeautotrim.com/usa/usa/tops/mercedes_hoods.htm
for tops

Potomac Germany Motor salvage located in Florida and Maryland-great used parts