Cheers,
I've just used a 8x60mm bolt in the meantime anyhow. Having replaced the grab handles with Honda rear rack and then GIVI pannier, all of which I got bolts with, I had a few different lengths (all M8)
I just like putting the original stuff back, though as I've arrived at this point due to putting pannier brackets on, I doubt I'd ever need the luggage hooks anyhow.
The amount that ebayers are looking for is ridiculous.