Anyone familiar with ATC-510 simulator?

I just bought one of these with the intention to gut it and use it as the
cockpit for a PC flight simulator setup. However, it still seems to work
and is fairly interesting to use as it is. However, I have no idea how to
use it as it was originally intended; what to set the xponder, ADF, com and
nav freqs etc. and what to expect.

My google search on it has not turned up much. Has anyone got any
suggestions for use or contacts for documentation?

Thanks. It's a pretty interesting antique.