I’m Interested to see the back and inside of the X-Controller.
As Neil said, those steppers won’t work with the stock X-Controller, But that’s not to say that the prior owner didn’t gut it and re-use the box and install new controller board, which may explain the extra power supplies…
Here’s a reference to what I suspect may be inside of the X-Controller box: ( from one of Neil’s prior comments even 
) One could wire into Arduino Uno pins 2-7 to be able to use those steppers with integrated drivers **BUT the closed loop part makes it a little more tricky as a 3rd Enable wire is also required (not shown in the wiring schematic, BUT it is present on the Arduino board Pin #8) **
Here’s some data and tons of photos of the internals of the stock X-Controller to kinda compare yours too and provide some guidance (following the assembly guide backwards) on how to open it up.