Thanks @Pete. Yes - this has turned into a real dilemma. I have run out of time to go and inspect it (I only saw it today) so have emailed to ask about the change gears, and whether it actually runs, or not. Following comments on here, I'm not too worried about the motor, but the rust LOOKS quite deep from the photos.That Little John might look rough but I bet there's a gem hidden under there. The paint is mostly intact with no big chips in the usual places. The hole for the tumbler reverse is not rounded off and there's no score mark from many directioon changes. The fwd/rev switch has a little paint rubbed off the red face but not a lot from many on/off switches. The 4-jaw shows no battle damage just a bit of crud and rust.
What I would be worried about is if it has all the change gears, since it's a change gear model not a gearbox model. If those gears are all missing, they'll be a couple of hundred to replace at least.
I've followed @dieselsamurai s "Help offered a cheap lathe" thread, and think there could be hope - but plainly he's more skilled at rebuild/restoration than myself.