I've just got a second hand Microrouter, and 4 minutes into my first test job, the spindle motor starting arcing, then stopped.

I've taken it apart and although one of the brushes is fine, the other one is at the minimum which would explain the behaviour.
So I need a new set of brushes for a Porter-Cable 3102 HD. I live in the UK, and I would like to get hold of some before Christmas if that's possible.
Anyone know of anywhere I could get them from?