Rarest A-Body Option?

I'd doubt the power window/lock on a Duster. Think about it, POWER LOCKS on the cheapest car Plymouth sold? The power window motors of the day wouldn't even fit in the door with the glass. Most of the new kits require the use of the 73-up doors due to the door latch being higher up and more forward in the door.
As for the hood mounted tach, it was a dealer add on and was also available (same tach sans Mopar logo) aftermarket.