Here's the story I read on a web site dedicated to those "1000" modifiied W126s:

"So where does the name 1000SEL come from? Well, somewhere in the early 1980s an Arab customer from Styling Garage ordered himself a heavily modified Mercedes 500SEL. When he received the keys he told the owner of the company, Chris Hahn, that his car was twice as good as a regular 500SEL. Well there you have it: 500SEL x 2 = 1000SEL "

Check this web site for pretty wild modified sel and sec. Some have held up and some I would imagine were pretty questionable even back then. Just furthter proof that money doesn't buy good taste.

http://500sec.com/1000sec/

Hint: click on the article section at the bottom of the page. My favorite is the Gemballa 500SEC with an absolutely stunning interior. Not sure about the steering wheel buttons but ...hey... this was the 80's.

I was searching through the above website and I think I found what should have been in the dash area of the 560 on ebay

http://www.500sec.com/1000sec/?postid=18

Pretty neat looking car - almost looks like a BMW 850 -except it predates it by about 6 years!