Jack Dover
That looks okay to me. I don't have lots of experience with grinding wheels, the one that is scratchy came with a grinder. It's also badly out of balance, I just assume it's a low quality wheel. Removed it because it feels like it's going to shatter any moment and because it's bad for bearings.

EDIT:

Bolting a grinder down will keep in place, however walking is a symptom, not a problem. I used to have access to a Baldor grinder (had no idea what is Baldor at that time), it was screwed to a flimsy bench top. A water in a can next to it was absolutely smooth and motionless. My current grinder is a new Delta, it's bolted down and even after many hours of dressing and centering a wheel water in a can on that table shows this nice waves interference picture, could be a textbook illustration. I don't think it will be more than a couple years before bearings will die. Maybe it doesn't affect grinding, but it's so much nicer to stand next to a smooth and quiet grinder that doesn't sound like a helicopter taking off.