[Geof]

Yes the drawbar should unscrew.

It is possible that the slight movement you are seeing is clearance in the spline or keyway between the spindle and the drive pulley.

You have a tool to hold the spindle: Does this fit on the top of the spindle, the parts that goes down and up, or does it fit on something on the pulley?

If it holds the pulley it is almost certain you are seeing the clearance I mention.

While it is not impossible to break things it does require a bit of force so don't go using 3 feet long breaker bars for loosening the drawbar.

The best way is to try and wedge something on the spindle tool to stop the spindle rotating while you use two hands on a wrench on the draw bar. You can expect that loosening the drawbar will take a good pull but it should be possible with a wrench no longer than 10 inches or so.

If you cannot wedge the spindle tool and have to use one hand on that and the other on the drawbar wrench position your self so the two are on the same side of the machine and you are pulling on one and pushing on the other. This way you are better balanced.

If you position your self so you are pulling on both when they come loose quickly you fall over backwards and crack your skull or the wrenches slip off and you hit yourself in the face. If you push when things come loose or slip you fall forward and mash your face into the pulley.