I was about to chime in on this thread, but Dave said it all. Trying to do it yourself will create more work, and will probably cost you more money once you take the shaft to a pro to straighten out your mistakes. If you can work to a runout (wobble) measurement of less than .010" and put a perfect weld bead all the way around the joint where the tube meets the yoke, go for it!
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!