That's some interesting stuff! Seems like someone has preceded us by almost three decades in successfully having a 128k logic board running without its AB. The video circuit seems pretty crazy stuff - does it output a standard composite video signal? That would be pretty easy to convert into VGA!
Also the power supply seems a common ATX one of some sort, it's a pity that the image is not in high resolution and it's difficult to understand exactly what cables have been connected just by looking at it. The video circuit is neat, though - the schematics is there and ready for testing!