Naomi
I have the same lathe and I too needed to fit a single phase motor as it came with a two speed three phase one.
The one I fitted was a good old British 2HP motor as you are asking for, this lasted about 20 years before it gave up the ghost and all I could find at the time was a 1.5HP replacement. This was never really up to the job and would stall if the lathe was very cold.
I recently needed to turn a 12" cast iron flywheel for my model mill engine, the lathe was really too fast for this so I decided to fit a 2HP three phase motor and run it from an inverter.
This is the best decision I ever made, it runs much smoother with hardly any vibration at all, and I can go down to about 10 RPM spindle speed with it.
The brand new motor was then only £76 on ebay, and I already had the inverter, but these can be bought relatively cheaply for a similar price to the motor these days.
http://www.ebay.co.uk/itm/172195074657
http://www.ebay.co.uk/itm/2HP-1-5KW-...cAAOSwYmZXJGmR
Would I ever consider a single phase again ?...........No Chance
Phil