[Ian Fawbert]

Tony,
I'm not even sure if it would work but could be explored. I have a mate who clips a lot of beef cattle for parading and showing (EKKA, Sydney Royal, Rocky, Melbourne royal etc). He put me onto the idea of the following to slow the clippers down. Perhaps the same would work?

A piece of board with a female plug which the extension lead plugs into. Mounted on the board is a dimmer switch which reduces the electricity going out to the clippers he has, thus slowing them down to a nice, slow (and quiet!) pace! Perhaps this option would work for your motor? It would be relatively easy for a sparky to make up.

Cheers,
Ian.