Attached is a photo of the solution I ended up with to add four casters.
First, I cut and tightly fitted four wood backing blocks from corner to corner between the flange and the base plate of the station.
I then drilled five holes per caster into the flange, and screwed the angled base plate of the caster into the backing block with five long wood screws.
Although I could have used bolts, the screws appear to be more than adequate.
P.S. The wheel hook has nothing to do with the casters. It's an accessory for the station that is fixed to it's side in one of several precut square holes. It allows you to hang spare grinding wheels on the side.
First, I cut and tightly fitted four wood backing blocks from corner to corner between the flange and the base plate of the station.
I then drilled five holes per caster into the flange, and screwed the angled base plate of the caster into the backing block with five long wood screws.
Although I could have used bolts, the screws appear to be more than adequate.
P.S. The wheel hook has nothing to do with the casters. It's an accessory for the station that is fixed to it's side in one of several precut square holes. It allows you to hang spare grinding wheels on the side.