Racer,
I am at the same point. I have received the plans and found a good local laser cutter who also is a well known scale builder.

I tried to e-mail to the address given on Wendell's website for details of the scale retracts but the e-mail bounced.

Wendell sent me these details to try:
"wdeverna@buckeye-express and darrellcnc for the gear."

I haven't tried to contact them yet. Maybe you could post here if you find out details