1958 National Tremo-Tone model 1224, made by Valco in Chicago.
This is the same company that made Supro, Bronson, Oahu, Tonemaster, and many others. Check out the video demo, and please read on…
https://www.youtube.com/watch?v=EUNcRI2QUPM
This is the rare late 50s variant with a 12AX7 instead of an octal tube for the phase inverter. It offers a variety of sounds with the full and fat Standard input, and the brighter Treble input.
Sounds totally killer for guitar with a sweet midrange voice, and is a favourite for harmonica players as well.
This amp is in nice condition and plays very well. It comes with the original cover (which is in beat and torn-up condition). I suspect it lived under the cover for a long time which might explain some of the discolouration on the tweed.
Condition: The cabinet is nice and solid and the speakers are in good shape and free of tears in the surround. It sounds great and is free of unexpected noises. The trem works but is VERY strong and it really pushes the speaker cones back and forth, so I don't use it.
The power and output transformers are original. Original Rola 7x11" AlNiCo elliptical speakers (285748, 285803). Grounded cord installed.