You might be in luck!
Since I've had to wait so bloody long for my new alloys
(due to arrive at long last, in under 3 weeks now), shop
has offered me a free set of locking nuts (besides other bits
too!). I actually already have some fitted but where as the new
ones are McGuard, ones on at the mo are seemingly just a unique
nut size nut (complete with the adaptor to undo them, that I
leave hidden in the boot - that way you don't loose it!)
You are welcome to them. Reply with your email / address if you like. Would just ask for a fiver to cover postage.