Unfortunately no, the motor is obsolete.
The Watermill’s are now obsolete all the available parts are shown on this page.
http://www.showerdoc.com/shower-spares/other-brands
There is nothing that is a good change over for a Watermill because it has left hand inlets the only shower on the market that I know of that has left hand inlets is the Supajet 100 and 200
http://www.shower-warehouse.com/new-showers/power-showers/supajet
Not a very good internal view
http://www.showerdoc.com/shower-spares/supajet/SUPJ-PARENT-1-Supajet-100
This has left hand inlets but uses a mains powered pump therefore the unit will need to be earthed.