Any suggestions for getting the spur out with minimal hitting with knocking sticks?
I'm used to fixing cars/custom bikes.
You've a mechanical back ground .. you'll understand my terms.
Try a good soak with as you've got it WD40 or likewise penetrating fluids, I've gone over to GT85 more as it's a little lubricant as well.
The threads stop one from shocking the shaft, tapping round it between 2 hammers, one as an anvil. There's clearance between the end of the shaft and back of the spur, you could try to pry it out, I've manage it once (not the done thing) with a spanner which just cleared the shaft of the drive, having the main back of the jaws on the shoulder of the spindle and levered against the back of the drive, at that time it was just tight, but yours may well be seized, could have to resort to the likes of a ball join splitter or something the same.
Wondering if you're strip the shaft out, let it soak in a container of fluid, even diesel I'm given too believe can work well.
The shaft could be heated gentle (only if removed) that it would help release the drive, displace the rust too. The shaft is no doubt small and it's the MT1 drive, so with whatever means there's a likelihood of damage/distortion... Last thing we want is to destroy the shaft .. drives are plentiful. One last thing I wonder how good the thread will be once cleaned, may effect the run out of any faceplate/chuck fitted.
Cheers David
