Hey all,
Well, I managed to sort of fix my broken air flap return spring.  I
broke it this morning.  At the suggestion of a listmember (sorry I
forgot your name already :( ) I went out to Pep Boys and bought a
suitable spring, a 1/4" by 1.5" jobbie that has the loops on both ends
for attachment.  Well, I screwed one end under the screw that attaches
the cable to the flap bar so that the spring won't go flying off
anywhere and then I attached the other end (well, hooked it over) the
oil dipstick tube mount that is on top of the fan housing (Vanagon,
remember).  There is a little lip on this mount that keeps the spring
from coming off.  It looks like a very secure method.  When I can, I'll
try to get in and fix it properly but this looks like it will hold up
for a while.  With this setup I can reattach the thermostat cable (which
I did) and the spring is strong enough to whip those flaps open yet soft
enough to not fight the cable too hard.

Thanks for all the suggestions.

Sean