Don't discard that one. It's very "fixable", but it will need to be removed from the rocker shaft so it can be clamped in a drill press vise to remove the broken off stub. Then the same tube can be plugged into the hole and silver soldered back into place. It might require a little careful re-bending to make it fit and clear the rocker shaft after the soldering job.
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!