what moves the fresh air intake flap?
 

hi folks, this is the fresh air intake flap under the cowl cover in my '77. i am using a non-A/C airbox (despite the A/C job's presence in my garage, thanks to DeliveryValve). seems like if it's open fresh air comes from outside and if it's closed, air is recirculated. never mind the blower resistors.

the flap rests in a partially open position. is it supposed to be controlled by a control in the cabin? i thought it would be the horizontal slider in the dash trim, but seemingly not. it moves quite freely, so maybe it is meant to open with air pressure from the blower. i haven't tested this because my blower's on the workbench, but does anyone know?

any good material for refoaming it, i'd like to hear about too.

http://www.lithic.org/tmp/DSC_0982.JPG