Hi Guys and Gals.
I thought my recent experience might help someone else in the future.
I have the CCM branded 75mm bar end mirror option on my Spitfire and managed to break the glass on the left hand side. Long story but basically, due to vibration, the whole mirror fell off the bike and was run over by following traffic.
The aluminium was scratched and the glass broken.
Happily, the name of the manufacturer is on the mirror. Oberon-Performance.
For anyone in a similar position they sell spares including mirror glass on their website http://www.oberon-performance.co.uk. I think it was somewhere around £15 including postage.