Hi Craig, Thanks for your input, I was actually more seeking information about the make of machine itself! As frankly I have no clue what it is. This is just for my own curiously.
The retrofit will be straight forward, I've done a few. I will be using the SZGH-CNC1000MDb (4 axis). These are fantastic and straight forward to set up. Their engineers are great and will also build the macro and supply the relay pack for the ATC.

The servos on the machine are actually Glentek AC servos and drives. These will be retained and I will use a step / direction to analog converter between the modern Chinese controller and the original analog Glentek servo drives.

If the original drives / servos give me trouble I will swap them out for Chinese AC servos and drives.

Should make for an nice machine when all done.