I have also used Eric Bergstrom's Bergytone BT-002 suction boxes.  They
have a 2-stage inline suction unit that improves motor cooling.  I have
used both the kits where you supply the suction unit (available on the
Internet) as well as the complete factory units.  His solid state 2-
speed controller is very nice at handling a slower speed for rewind.

Terry Younce