Here we have a very cool Masco amp, a model that has found its way into the hearts of harmonica players due to its unique tone. If could be used for guitar as well, but the character of the amp does suit it much better for harp.
The amp has been gone through by my friend who has been building and repairing amps for decades. It is working great and has no issues. All the tubes are solid.
The amp for years had no bottom plate. My amp tech friend fabricated one out of the grille from an old movie projector speaker cabinet.
Chances are, if you're looking at this you know exactly what it is, so I think I'll leave it right there!