More frustration, really. Have the M16 mount UL4 calipers. They work finer but pull a little right.

So I checked the mountings and shims - just a little bit asymmetrical on the right and they never really let go. SO I shimmed them out a bit - and in a bit - and out a bit - and in a bit - and just couldn't ever get it quite right.

So it;s back to how it was, except there's now a rattle from the wheel arch.

Ah well. Track day Sat so will just have to be a little gentle.....