So far, I've only put one LED in our '51 as an experiment. I'm tired of the flashlight method of reading the instruments at night, so I tried to brighten things up a bit. I had half old and half new. The results were somewhat disapointing. It was not brighter, but the light was white instead of yellowish. I need to find a way to get more light to the instrument cluster. White letters on a silver background is probably not the best idea either, but so be it.
No problem with wiring so far with these low power bulbs. I would think it would work better for the wiring as the current draw is much lower.