On Ebay motors there is an official MB 602/603 engine manual

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=600940635

I just bought the same manual new for $87 LOL But it is extensive.

As for a CD this deal is about as good as it gets

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=600940635

I just bought one for $80 including shipping, in spite of the low starting price and the No Reserve it seems like you can never win one of these auctions for less tha $70 I watched them for at least a month before I anteed up. Never having actually seen or used an authentic MD CD it appears that mine is a pretty good facsimile. At least it appears to as confusing in the same ways that the official MB version is said to be in some of this forum's threads. P. S. I haven't been able to find a Haynes for a 126 or a 603 don't think they have one.