If you want to save yourself some time and effort, consider buying a motor kit. I've wound a couple helicopter motors that needed an extremely low RPM/volt using kits from Scorpion Power systems, and it makes the job much easier. It's still a fiddly process, but since you get the casing, shaft, bearings, etc it's nothing like trying to make everything out of resin.
I'll look into that. If I can find some good old motors or motor casings I'll probably get that instead.
That'd be cheaper, although removing the existing windings can be a huge PITA.
Honestly, you might just be better off buying an automotive alternator from a wrecker and using that. It'd be the cheapest and least time consuming.