We have these surplus parts available for sale:
Beechcraft Air Vent Control Cable and Knob
Purchased new for my 1964 Beechcraft B33 Debonair to fix a problem with the air scoop not staying closed, but now don't need it. Also fits N35, P35, S35 and most Debonairs--late A33, all B33, and early C33. Probably Travel Air as well judging from the part number.
Part number 95-380007 $350.00 plus $5.00 shipping.