Skoti, great price but postage too high @ £24 (works out same total price as new Honda from Silvers)
Ken, good point, wasn't bothered about 12mm originality but never thought about the socket issue.
I think in light of all the variants in the nut make up/design/strength/etc as discussed in this thread, I'm going to re-zinc the existing nuts to be on the safe side. Good debate though and learned a lot - hopefully been beneficial to other members too. Thanks for all the input and advice.