Jack
The fantastic fans installed where I believe the 2000 series with electric lift and remote switching interface.
If it's your vent cover you need they are available and fit all the fantastic vent series check on line or any good RV store.
If the motor is done your best bet is a new unit complete.
However if the controls or inner facial are done you may be better served by an upgrade kit which gives you the inner facial screen .switches thermostats, fuse holder and wiring there are several different upgrade kits to pick from I settled for the basic thermostat kit and it works great check on line at Amazon for options.
Hope this helps
Eric