And something Crazier!
I'd managed to roll it about to try to loosen the caliper but it wouldn't budbge. It was stuck in my drive and staying there. I sat it on the centre stand and came in to search what was needed before pulling it down (or lifting a spanner).
It was stuck fast when I left it!
When I dropped it of the stand just now to remove the caliper bolts- it was free as if nothing happened...
Which is pretty cool but I hope it's not going to seize on under use