I think that's a bone stock Silhouette bass, he may have just lost the knob on the mode switch (which was a rotary switch, looks like a regular pot with the knob on, there is also a standard 5-way switch closer to the neck pickup), and the Silo bass always had a standard nut (compensated nut from 2006 on).Nice catch! Looks perhaps slightly customized with the 3 way switch and probably a regular guitar nut.