73 Duster 4 speed Reverse Lights Wire Harness Question

Looking for some feedback on this, Brewers is out of stock on their 68-72 back up switch harness with no ETA right now. I checked Year One and they list a 68-70 harness 4psd and 71' harness 4spd, any chance you think I can get this 71' harness to work from them? Ive also found a book store and bought the 73 facotry service manuals to have so I can start to trace wires and figure out where I need to tap into on my application for this harness, I'd like to not hack up the wiring if at all possible to get these reverse lights working.

https://www.yearone.com/Product/chrysler-a-body/l38480