The Rimmer Bros website lists them by the MG Rover part number, SRB101xxx.
https://rimmerbros.com/ItemList--Rov...Parts--m-21312
Last I heard, the ABS modules for cars with traction control were hard to find, I don't know if this is still the case. You might be better off sending it repair if you can manage without the car for a week or so. There's several specialist companies out there like
https://www.actronics.co.uk/abs-ecu