Hello Mike,
The last instalment was delayed, Diane says it will be in the next issue.
The motor I used was from a scrapped 80W 12V Shurflo shower unit , I just replaced the corroded front bearing. Something like this would be ideal, but you can buy a Shurflo pump for half that! I suggest shopping around for surplus motors. Ebay is swamped by small high-speed motors, you need a hefty one rated at about 80 watts 3,000rpm.
I'm I made my own bespoke controller.
The relatively low current (stall current 8A on the original) will make an expensive high-power controller a bit OTT. If you search eBay for "reversible 12V motor controller" you will find a lot of suitable candidates.
This one should do the job, and the controls are suitable for making a simple remote handset:
http://www.ebay.co.uk/p/10-50v-40a-PWM-DC-Motor-Speed-Controller-Cw-ccw-Reversible-Pulse-Driver-Te535/760730213?iid=262521215361
I look forward to seeing the finished result.
Neil
P.S. video of Southam if you scroll down.
Edited By Neil Wyatt on 15/08/2017 10:01:25