Managed to find a set to fit the Fazer. There are advertised as fitting the MT09, no mention of the FZ6 S2, and I couldnt find any that looked remotely like fitting. I measured up my existing bar ends and then rang M&P and asked them to check the measurements against one from the warehouse. Feedback positive, I bought a pair, and fitted them this morning.
They fit fine, so if anyone else needs guards, these are a straight swap for the existing bar end weight