74 Duster AC - Factory or dealer add on?

I'm wondering what exactly I have. I bought a Duster disassembled and it had air conditioning. The problem is I don't know if I have factory AC or dealer installed AC. Can anyone tell from this picture of the under dash vents? I can see where this bolts up below the dash in the AC car. I have another 74 Duster that I'm transferring parts from, but it doesn't have AC at all.

Cley

looks factory to me...............