I think you can. Alex Pomar at Kenwood Chef Restore is the best person to approach. If it's possible he can do it.
That aside the old centrifugal control system was robust and simple. The machines do tend to speed up a little as they warm up but you can adjust the 2 screws accessed through the vent hole on the underside of the motor unit to slow it down and stop splashing especially when first starting up.