Ok, according to his reply he has both the MRF-350 base station and the "Aeros" remote - which is the MX-850, if I'm not mistaken?

He also got in touch with the guy who apparently installed the system and programmed the remote for him in the first place and asked for the program - but what the installer sent me is a folder full of .mxg and .mxf files (with a few .wrz files for good measure) - these are configuration files used by MXEditor, right?