Good job, Daniel.
Unfortunately it's horribly complicated :-)
Just yesterday I've assembled a do-it-yourself-in-10-minutes-or-so book scanner as shown here:
http://www.infanata.org/news/1146100...-pomoshhi.html.
The page is in Russian but the pictures are most important.
Here's Google Translation:
http://translate.google.com/translat...istory_state0=