Used shifters are available on Ebay, and brand new ones from Novak. No point in wasting time and money welding on one as it destroys the tempering of the metal and it will wear very rapidly. That worn metal has to go somewhere, so it falls into the transmission and makes a good grinding compound along with the grease, which wears out the gears.

www.ebay.com/itm/196374978184?

Enlarge the pictures to see what the shape of the bottom of the shifter is supposed to look like.
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!