Well, if we are brainstorming... I would get an old vintage cassette deck... This way you will have two "matched" meters. Many of the old ones were illuminated... Of course you will need other parts/components to complete...
I remember back in the day, when I built an led power output display... The kit was like $7!!! If you could find something similar... Probably be a little more expensive today!!!
Funny, I had similar thoughts of getting/building a power Meter (or two or three) just a few days ago...
Please keep us/me informed of the progress...
George