Smartify 50s low-voltage lighting system
I would use the system as it is and add a low voltage relay that the computer controls to fire the existing relay. With this method the existing switches would still be functional as an overide, one example might be similar to an arduino relay board using the arduino micro controller my grand son and I built a 12 channel Christmas light controller, in your case you use the relay to bypass the switch and pull in the larger relay using the existing low voltage control.