. That is one mean piece of iron.
As far as fixing the existing controls goes I have no idea.
I will tell you that if you want a new controller that will run Mach3, the DSPMC is a nice choice. I have one running my BTC-1 mill and have the other going onto my Tsugami chucker lathe conversion.
I will be attempting to integrate the tool changer which is similar in style to one of yours and I don't see any insurmountable obstacles. The lathe threading is working on the DSPMC.
If you have more questions on the DSPMC feel free to ask, If I don't have the answer, Rufi will chime in when needed.
Mike