Re the heel board bolts - after having given them a while soaking in Plusgas or the like (and if using Plus Gas you want Formula A) try and tighten them a tiny bit (that means just a smidge or a tweak) before trying to undo them, this is often enough to break the rust seal.
Something told to me years back and seems to help is to do things up just a little before you undo them..........
Probably something to do with not pulling loose corrosion into the thread, but letting it drop out.












