Long shot, but I don't suppose anyone has some spare drum backplates from a Morris Ital axle (as in the donor used for a Caterham Live Axle)?

Have a very warped nearside backplate, and finding it hard to get a replacement....

Cheers

Be aware there are several different types of Marina/Ital rear brakes. I suspect what you are looking for is the 9" self adjusting type from the Ital

Cheers, mine has manual adjustment of the brake shoe location.