I've got about 6 of them kicking around but the trouble is they're specific to the about of spokes on the wheel so non of them fit my wheel. I tried eBay (and Wiggle and Chain Reaction and Amazon......) but nobody sells one for a 28h freehub wheel. I could just cut the little tabs off, it's not going to go anywhere it'll just spin. But my OCD won't let me, somewhere, there must be the right bit of plastic.
AndyRM - thanks for the very kind offer but, as I said above, I'm pretty sure the spacing of the attaching tabs will be wrong (I spent a very frustrating half an hour last night trying to get one to fit).
Bugger it - I'll just have to leave it off and go eau naturelle!
Most get binned by LBS and Mobile Mechanics during a service as they age badly and get brittle.... hence why some come in and go out without them. Getting a replacement to suit is a PITA and most customers are happy that their bike is serviced properly and their chain will not come off into their spokes....