Originally Posted by Mark_h

OK.
So question is what do I do now?

a) spray wd40/brake cleaner/brake fluid/unicorn blood or similar into caliper body to free up the piston

b) just cleanup what I can see, push it back and hope it doesn't rip the seals to buggary

c) go buy a new caliper/scooter

Constraints:-
I have no brake spares other than fluid so ideally want to get it better without needing new seals, banjos etc