That's the problem, the motor is about 130mm square and is fits behind the gearbox.
These motors are no longer made and second hand ones very rarely come up for sale, I did find a 3 Phase motor from the Netherlands(ebay) so jumped on it.
Not even sure if it works yet(waiting for VFD and other bits and bobs from Ali)
If the motor is no good i will indeed try and find a suitable 3 Phase dual voltage motor, but it could be a bear if it's much larger than the original.