Well, I decided to fix it rather than bodgying it up and possibly causing further damage.
I got an impact driver and it worked a treat for getting the brake drum off. I have previously used the screwdriver + mallet method, but I think the screw heads are too far gone for that method now.
When I disassembled it I found that the bearing had been spinning against the spacer on the drive flange and worn a groove in it about a millimetre deep

. The inner race had been spinning on the shaft and had then chattered after that, so the drive flange was trashed. I got a spare out of the parts car though. I checked pre-load according to the method in the howto (thanks doc) and it was good, and it all fitted together nicely, so it should be sweet.
I also replaced the brake hose and all the balljoint dust covers while I was at it because I don't know how old they are.
Thanks for all your help guys.