After much experimentation I believe the following:

1. That the principle of operation is that the belt loosens up and
doesn't grip the turned drum.(I might be wrong about this)
2. After loosening the belt tension all the way, my unit works fine.
3. I broke off two rollers and found a way to split the locking nut in
half (that secures the eccentric belt adjuster).
4. This is a higher level of destruction, even for me, than would be
typical for a fix of this magnitude. It is an older unit.
5. I guess I don't care about the adjuster so much since I want it
loose anyway.
6. I should buy a Mk II unit and keep this one for a spare.
7. http://www.ganssle.com/jack/ is an excellent website. Wonderful
writing, sublime experiences, very helpful manuals et al. Thanks Jack!

So for now that concludes my wee experiment with the Autohelm 4000.
Thanks again for the help.

Otter