Tom - this worked a charm. I just dremelled out the heat welds underneath the little square bucket and I could remove the bucket, and the two covers with their "legs". I superglued the damaged leg on and refitted, but it kept hopping off the damping cogwheels because the superglued leg had no natural spring action. So I wedgied a little off cut from a plastic ruler in between the leg and the cover to create outward spring pressure on the leg to hold it in the locating hole.
Works perfectly now.
Thanks very much for the pointer - I understand this is a pricey part