Additional thought crossed my mind... IF I installed dependable, quality LEDs in my inst' panel that should burn for 100K hours, I would be tempted to reroute the orange wire to hot at switch on so the inst' panel lights up with/when like todays vehicles. We pretty much forfeit the dimmer feature with LEDs anyway, right?
All other illumination could and would stay OEM.
Some LED's are dimmable. Just gotta get the right ones if you want that feature. My dash lights were so dim with incandescent bulbs the LED's made it just right so I don't really need a dimmer