This is a simple electronic piano from GEM (Galanti Elettro Musicale), an Italian company that previously had made a lot of combo organs. It uses a concept similar to that of a combo organ, with divide-down architecture (using frequency divider ICs this time though) and passive filters to create the four sounds: Piano, Harpsichord, Honky Tonk, and the Bass sound which is always a different sound from the rest of the keyboard and cannot be altered. The addition of a simple AR envelope makes it a “piano” instead of an organ.
Work done: replaced diodes in bridge rectifier diode ring and the small number of electrolytic capacitors in the instrument, replaced one bad divider IC, cleaned key contacts and buss bar, repaired a few broken plastic keys and replaced one damaged key contact spring.
Tip: this is a general-life tip. I just want to tell anyone reading this to stop messing around with super glue. Switch to two part epoxy and don’t look back. I use it constantly, to repair everything from synth keys to houseplant pots that my cat knocks over. Just yesterday Darian used it to fix his glasses. Every time I use it I lament for the fools still trying to repair things with super glue.