Hi tower,

This person seem to carry just about all the shop/repair manuals
for all makes of Mercedes and other cars. However, I dont know how extensive and/or good they are. Just go to the following item on Ebay and ask him through an email whether he carries your W140 manual.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=34227&item=2450308772

Good luck.