As stated, the 1974 cars haven't received much notice until recently. Not much information on what is correct and what isn't. My 74 Charger has this same black air cleaner in the photo I posted of the red Charger Rallye although I bought an orange one and I can change it. My brake booster ( original as far as I can tell) is black. I too am trying to get mine as original as possible but it won't be perfect. Enjoy the car.
Terry