Digging a bit further I find that the this was covered in issue 86 (November 2002) and was by Vasilii Zakharov.
He is using a Hoover control unit and motor from the same machine. He also provides a schematic and hints on the whole process.
So I have the original work.
What I was hoping for was to find that someone here has done this and lived to tell the tale.
Maybe the kind of Madmodder who knocks up single-to-three phase converters out of old capacitors etc.
I have a selection of motors from old washers etc, but don't know how to utilize them.
Bill,
...Do you really want a noisy, high-speed brushed motor on your machine?..
In a word 'yes'. That's why I posted the query.
A bit of noise is the last of my engineering worries. Some experimenting with multi-groove pulleys + the electronic control will soon find a relatively quiet speed range.
AndyF,
Thanks, I'll have a look there.
Dave.