[giles]

Thanks for the advice. I have bought some PB Blaster (and ordered something called AeroKroil, which is also supposed to be good at freeing parts) I'm going to squirt a little of either at the pins which are only rusted in at the far end (the end furthest from the flattened head), and try the twisting technique. I think the reason the brakes were juddering was because one of the pads was also rusted and not moving towards the disc when I braked, this caused the disc to deflect slightly due to pressure from the moveable pad. Can't wait to replace the pins with nice new shiny ones slick with just a dab of silicone grease!