I have spent many hours trying to dream up a fuel gauge that would look original but have reliable workings, including some barber pole arrangement like a 64-66 T-Bird speedometer or coatings that change color with electric charge. Unfortunately my technical know how falls well short and I didn’t come up with anything. I am using the original gas gauge system but installed a bit of a cheat that I hope will keep it working in case of sending unit problems after sitting for awhile.
A lot if cars retrofitted universal dial temp gauges in the original hole. They obviously don’t look original, but a compromise might be to replace the facia card with one that matches the ammeter and oil pressure style.
I can dig up the temp gauge guy contact info if needed.