MoparX, I just simply hammered finger grips at the most, two times each while using the original wart holes as a centering guide. The trick was controlling my applied pressure to the swing. Sought of like knowing how much pressure to apply to a hand shake. You don't want to menacingly crush the other guys hand nor do you want to be fleetingly soft. I guess now thinking about it afterwards, I could have easily fabricated a hammer stop sandwiching the ring on both sides to act as a yield.
The steel round bar was some left over piece from a grommet maker I had laying around which is hardened and the hammer was a rubber mallet. I didn't want to crush the wheel ring or I'd be out a cool whopping $16 dollars.LOL. I have formed quite a few things using found, discarded shaped objects that serve well as a tool.
