No argument Darren, a VFD would be 'nice'. But spending the kilo-bux, or whatever, on other toys would be nice too.
He already has 9 speeds on his lathe, 18 if he changes the belt. If he is like me and the primpary purpose of having the lathe is to enjoy using it then a 'nice' project would be to turn up a couple of pulleys.
[thinks] Hmmmmm, there is a Triumph Herald gearbox under the house, I wonder if I could interpose that between the motor and the lathe? That would be 36 spindle speeds, 45 if I use reverse..

[/thinks] That aint gonna happen...

JB, or a very simple electrical circuit and he wants to know where in his country he can buy a 10K resistor!