Per advice I received reading up on coolant loss without warning and other bad things, I’ve decided to keep the dummy lights/heads up display and relocated it to the stereo’s former home.
The cable is long enough to pull all the way down and through the dash into the area where the stereo used to be.
The HUD is a little taller than the stereo opening and not as wide. It took some trimming to get it to fit. I stole some plastic trim from the old parking brake surround to fill in the gap.
And viola. A couple self tapping screws hold it in place (not looking for a show winner here, but I think it turned out half way decent).