That should be an easy fix. Weld or braze a 1/4" fender washer into the rusted area and do a little cleanup work on the weld with a die grinder or a Dremel tool. With a little sanding and paint work the fix should be virtually invisible.
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!