Hi Mal,
Thanks to Steve for giving the link to Engineering Carbon Products Ltd. They now sell the brushes singly or in pairs or a full pack of 4. I recommend dismantling the motor first to assess how many you need.
Regarding your media question, it's best to start a new thread about that in the ICE section.
I'll send you a PM with the contact details of the Hounslow based air con. mobile specialist.
Simon