Ian Wright does these. There are two types, the flat back early type which wore if they came loose, and then the countersunk back type which helped stop the drum rattling around
Without seeing it. My first approach would be to only try to undo it with a hex socket and not a normal 12 point socket. I would probably play some heat on the bolt head first with a fine nozzle acetylene torch. Heat the head to a dull red, so that the heat transfers to the thread. Allow to cool for a minute or so, and it will probably undo quite easily. You could even mig weld a bigger nut to the old head. If it has to be drilled out, do it from the inside of the drum. Ron
Forgot to mention, the wheel rim and spokes are fine (as is the paint), so welding a nut onto the hub is too fiddly. Will try a gentle tap with the impact driver on a better socket first.
