Source for "Document Assistant" for LJ 1100a scanner?

I just scored this very nice attachment for my LaserJet which lets me copy
from the front. There's also a "scan" button, but it requires software on a
CD that wasn't included, nor does it seem to be offered by HP.

This monster of a link will get you to the basic intro page. The drivers HP
have available are for basic printing and do not include the multifunction
bliss I'm seeking -

http://search.hp.com/query.html?col=...1100a&oc=12006

Would you have any suggestions for finding this CD? The usual haunts such as
eBay haven't turned up anything. It'd be marked either "Document Assistant,"
"1100 All-in-One" or something cryptic. Thanks.