A rust repair patch panel for a 58/59 pickup fender can probably be spliced into the bus fender if the eyebrow area is too mangled to straighten. Unless it's had a really bad hit, chances are a repair like that will be less expensive that replacing the whole fender.
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!