[Mgs] Heater Air Control

[Mark]

Here is my first post regarding my recently acquired 67 BGT.  I was 
sorting out the heater air flow control mechanical switch this weekend 
and ran into a problem.  The spring on the shaft of the air control that 
holds the knob is missing.  Someone in the past had put a set screw in 
the plastic knob that fit poorly in hole in the shaft that held the 
detent.  The switch works but not well.  I see that the usual sources 
don't have the replacement switch and the plastic won't hold the set 
screw for long.  are there any good options to fix the shaft?  Maybe a 
replacement spring and detent?  I also have minimal flow of hot water 
through the heater core and have ordered a new heater control valve.  I 
need to flush the cooling system anyway so I will replace the valve when 
empty the radiator.

Thanks,

Mark
Nashville