Per one of the comments I made on that old thread, my gut feeling is that the circuitry that drives the Lisa's monitor might need very little modification to work with a Mac motherboard; both systems had about the same vertical resolution and frame rate; the only real difference would be the pixel clock (IE, number of pixels per line, which in this case would be 512 vs. 720) and that's something that you can generally change, within reason, without modifying the monitor. Does that adapter board that's between the Mac motherboard and the Lisa's card-edge have any active components on it? (transistors, etc? I'm not sure what that white thing is, is it by any chance a piezoelectric buzzer replacing the speaker that's driven by the Mac's analog board?)