You can download a brochure here:
http://www.jensen-optical.us/four.html
The accessories are described there.
Missing parts are also listed there.
Here too:
http://www2.durst.it/shop/prodtitel.asp?prodcatid=4
And here is a user manual, though it is in French.
However, the names of the parts can be helpful, even if you’re not that familiar with the language.
http://manuelsphoto.free.fr/
Best regards,
Otto!