1972 Plymouth Duster 340 Firewall Help!!

Hi,

A friend is selling me a 1972 Plymouth Duster 340 4 speed, I check all car and is matching #'s The Vin tag, door sticker and radiator support match, I have to see the rear panel driver side under the package tray that have also the last 8 numbers, but I have a doubt, the car have air condition but when I saw the firewall seems differents from others 72 plymouth cars that have A/C, the heater blower motor and the fittings hose of the A/C that come from the firewall I think that is the same from a 74 Duster, I believe that the car is not original and something happen with it, so If anyone in this forum can saw the picture of the car that I want to buy and confirm to me that the car have a 74 firewall advice me about it. I dont want to buy bogus car.