Here is a scanned copy of the full owner's manual:
http://www.deutschermowers.com.au/owner%20and%20part%20manuals/r230_r360.pdf

It includes an Illustrated Parts List, and instructions for most routine adjustments.

I'm sure people will be interested if you take a series of pictures as you go about resurrecting it, and post them here. It should be a good way of attracting the attention of somebody who's familiar with the machine, too.