I am sorting and clearing lots of stuff. Dug out my old Heathkit
AR-15 Turner Amplifier. Seems to work well, but some of the
backlights for the front panel are burned out. Is it worth the effort
on this thing to try and get the bulbs and replace them?

It was pretty much state of the art in the late 60s early 70s when it
came out. How much has it been left behind by new developments?