Just a follow up for anyone in the region . . .
I discovered that Brownings Suzuki in Melton Mowbray used to be a MG Rover dealership and at least one mechanic there dates back to Rover days.
They charged £120 to replace one arm supplied by myself.
I didn't get a reply from
https://mgroverrepair.co.uk/location.html online enquiry form.
-a