Let me suggest you take the project one step further. The ball end of the shifter is hardened to resist wear, and welding in that area has probably annealed (softened) it. It's going to wear pretty quickly. There's a casehardening product called "Kasenit" that is used to surface-harden parts like the flintlock rifle frizzen that the flint strikes to fire the priming charge. If you have access to an acetylene torch I can send you a small quantity of the hardening powder (I buy it by the pound) and you can re-harden the ball so you won't have to make another shifter pretty soon. If you can scratch the area around the ball with a file, it's going to be too soft to last very long.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!