I have started to Retrofit my BTC-1. I have gutted the control cabinet I left the wiring from cabinet to cabinet intact. It is in very good shape for 30 years old. I plan to use the old servo's. I originally was going to use the original VFD but it went BANG. So I replaced that with a Vector Drive. I have installed the new Click PLC with with 2 additional input modules and 1 additional output Module. All are wired to the inputs and outputs I plan to use. I still have to wire up the cnc4c B.O.B. Here are some pics