Those shafts are definitely junk, and so are the rockers- - - -especially after mutilating them with a belt sander. It might pe possible to ream out the rocker bores and press bronze bushings into them, but the radius of the tips are critical and need to be the same for all the rocker arms. There's a fixture for most valve grinding machines that is able to resurface rocker tips correctly- - - -or at least make all of them match. It looks like you need to go shopping for a complete rocker and shaft assembly- - - -they show up on Ebay pretty frequently. Once you come up with a complete replacement assembly, you're going to need to address the source of the lack of oil flow that caused the original shafts and rockers to wear out- - - -that assembly has run dry for thousands of miles to do that much damage.
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!