I got a old sheet of suitable steel (I used an old front brake shield) and made a plate, approximately this shape
Which fits snugly and doesn't move, given it sits inside a flared section, also the tension of the anti rattle springs pulls it tight. It's a bodge, but a sort of 'professional bodge'. Fully intend on replacing the rear hub and in doing replacing the backplate for new/good as new one, I'll be stripping and repainting the rear axle this summer. Might get a mate to weld on a shaped washer or something as well on the new backplate to avoid it happening again.
If you're already not aware, Vx changed the design, as earlier cars have a slotted hole, the MFL onwards get a straightforward hole, with a washer, with slot inside, which is a superiordesign, as the hole can rot all it likes, as can the washer, when the washer corrodes, simply replace. Easier than replacing the backplate every ten years or so
The image on the right shows what kind of hole was torn into the backplate as the pin dragged and ripped the thin, rusty metal. That happenend on the way
to the MoT, as well. Nice timing!