If you get no bites on this odd one-off kind of unit, try emailing Clarion:
http://www.clarion.com/ . I recently emailed Elenco about an old power
supply. They sent me some PDF's of a hand drawn schematic. It was just
what I needed to fix it. I would have fixed it without the schematic.
It was a lot quicker to be able to follow the diagram as to what part
came next. (It was a shorted reverse polarity diode on the output.)