Vinegar - one week later.

I wasn't sure what to expect.  The vinegar was definitely doing something because the colour had turned dark brown (the rust magically dropping off?).

So, a quick wash off in water was in order.  The parts were coated in a grey/black residue which needed washing off and a quick rub with a wire brush.

The pliers will rust quickly after being in the vinegar so wash them, and WD40 them, straight after.

The next step was to tidy the threads up using a thread chaser kit.  A tap and die set would also be fine for this but I didn't have a large enough die.

This is a great kit - not that expensive either considering it's Snap On, and it has got me out of a lot of trouble over the years. 

It has slots placed within the thread of the "chaser" nut so that any swarf cleaned from the threads can stay away from the bolt, preventing further damage.

You can see the slots more clearly here on the tap version.

I'm pleased with the results.  Not all the bolts have come up to this standard but I'll perservere and replace only the parts that I need to.