Just to follow up - I received the new motor brush assembly from Motion Systems today a mere 24 hours after talking to them.
For $16 you can clean and refurbish one of the older actuators with a new brush assembly (p/n 79633-004) - and I'm sure that their service for complete motor replacements is just as good.
Jim Sharkey
RV6 - Heading to the airport for wing assembly! From Rosie: I just bought a new set of brushes on 12 Oct 2011, no change in price, part & contact info all good ;-)