While I was on a roll in 2014, I got the idea to modify the speedo and tach to use LED strip lights. I found some red lights that were in strip format and rated for 12v.
I had to develop a way to remove and install the bezel. I ended up making a fixture to mount the tach or speedo to my lathe. Then I created a tool that I could mount on the cross slide to either unroll or roll the bezel on. I spun the chuck by hand slowly to accomplish the task. I don't have any pics of this process, but might update this with a few pics fo the tools.
I was interested in incorporating a diffuser of some sort so the light would be a bit more even. I ended up machining a couple of rings out of plexiglas to act as a diffuser.
Once I had that figured out, I mounted the strip - it's got adhesive on the back - added a electrical connection and closed 'em up.
The final outcome. I plan to add a dimmer knob somewhere for these.