[Milsurplus] LM-18 and AC PS Questions.. More

[J Forster]

I picked up a  CBLC-20104-A  AC Power Supply and LM-18 Frequency meter a
few days ago. The power supply has a blanking plate over the meter hole,
which appears to be factory original, and a pilot light in the center of
the plate.

Does anyone know if the metered version was just an earlier version or
what?  Also, are the AC Volt meters available?

Thanks,
-John