The UVW will be commutation signals for the drives. (brushless motors are commutated in the drives, not in the motor).
If those signals exist then the choice of drives is much expanded.
Is there a DC power supply in the system, or do the axis drives take AC input?
I suspect that the easiest solution would be
Granite Drives
though cheaper options include the Mesa 8i20 (requires separate DC power supply) and "Whatever turns up on eBay at a good price"
It might well be simplest just to find a stock of spares of the original drives.