Got tired of pulling apart my McIntosh C-26 to replace the dial
lights, and looked at LED's as a replacement.

Digi-Key has several drop ins, of various voltages and luminary
output. They tend to be a bit pricey, though.

I also found this:

http://superbrightleds.com/

Direct drop in replacements of many popular AC and DC pilot lamps.
Many with multiple voltages from which to choose, and assorted colors.

These will also work with a variety of receivers.

Some will benefit from scuffing with fine emory cloth or steel wook
to reduce beaming. And some will also benefit from an aluminum foil
reflector over the bright spot to effect dispersion. But they're cost
effective, and of sufficient lifespan that you will likely never have to
worry about replacing one again.

Not applicable in some FM receiver stereo pilot circuits, but they
work in damned near anything else.

I've got them in my Frog, my Halli's, Nationals, and several pieces
of test equipment.

This outfit also supplies raw LED's for custom applications.