Rally dash heater controls

So I guess I learned something new today. I was under the impression that 67 to 69 and possibly to 72 were the same.

I had no idea that 67 was unique. I will have to pass on the 67 only unit to someone with a 67 because my car is a 69 valiant with a 69 barracuda dash swap.

Care to show the difference between a 67 and 68/9.... I am not challenging you but I would like to know for my info for the future of parts hunting.

Thanks so much. :p