Thanks Bryan, will do.
Also I've got another old caliper with a damaged bleed nipple I'm looking to sort.
The nipple has been broken at the top but has a reasonable bit still sticking out to get hold of.
It's been soaking in penetrating oil for a while and I wondered whether sticking the caliper in the oven for a while would help to free the nipple before trying to loosen it - what do you think?
Cheers,
Andy