heater valve etc

please help:.
i sure could use some under hood pics of a 72 swinger heater valve, where its located, how, etc. mine did not have one when i got it. it is a factory ac car. everthing else is there.
Q1, did it have a heater valve to interrupt the water flow to the heater core
Q2. what it looks like (factory) where its mounted
and anything else that would help. im ready to put back together

as you send me a pic of under the hood, what is the small chrome electronic box that is on the firewall to the right of the brake booster. about the size of a cig. package. ?

thanks ahead of time