I had a scroll through yesterday but also searched for the wrong thing. I've now looked in much more detail thanks and found a 'Caliper Wear Plate' which looks like part of the solution and will reduce the slack and twisting of the pad and spacer plate. If you note where my retaining pin goes it is the central of 3 holes. I've seen on some pictures all 3 holes used?
So a good start I'll see how far I get with Wilwood.
This picture shows the stainless plates and also all 3 holes are used which may stop pad 'rocking'. Like but not exactly the same as my calipers though.
Yeah I got my willwoods off of Dave that’s wot made me think he might help,if no joy gis a shout as ive got mates in the car game that should be able to sort you out with the bits