1968 Barracuda Heater control button

i am installing a Classic Auto Air AC system. It is designed for a non AC car and uses the OE dash controls, but has a replacement fan switch that takes a end button like the ones on the control levers. That is why I am needing a third one.
Very interesting. Got pics? I can't imagine how they get a/c functions from the OEM heat only controller. If the knob is worth 8 bucks shipped via paypal, PM me.