Where can i find parts for a mercedes benz 280SL in CA?

Here are a few source, on the ground and on line:

http://www.sltechw113.com/
http://www.millermbz.com/
http://www.budsbenz.com/catalog/200
http://www.mercedesdismantlers.com/

There is a new Classic Mercedes center (owned by Mercedes) in Irvine, California. They have ALL the parts and do repairs, restoration and service on cars like that.

Here it is:
Mercedes Benz Classic Center
9 Whatney
Irvine, CA 92618
(949) 598-4850

online, ebay, or go to a local ma and pa shop to order some. Hope this helps! check search engines for 1971 mercedes-benz car parts. Careful, check out all prices, some people inflate pricing.