Here's a supplier from the my old battlebot days. Available are various motors & an E-tek replacement designed & built by original E-tek motor designers. The E-tek R is a great value for power/weight brushed PM motors.
Etek Motor - Robot MarketPlace - Briggs & Stratton
Great resource for mechanicals, drives, DC motors, speed controllers, & battery packs. Well informed & friendly tech resource as well!
Ryland,
Looks like a LEMCO's coil armature. Check out @ 6:44.