My 1956 Chevrolet Task Force 3200

[_Ogre]

looks like a nice truck. floors look stock and rust free for sure
what are your plans with it?
if your vin starts with V then it is a factory V8 truck

to the best of my knowledge... ac was introduced in 59 in trucks
it was a stand alone system that mounted on the floor, below the heater, center mount in column shift trucks and passenger side on floor shift trucks
stand alone; as in it was ac only, with it's own fan and switch.
totally separate from the heater and heater control