here's your fix:
1: wire brush from walmart
2: little higher than med grit sand paper, 1 piece
3: lil carb cleaner
4: jb weld
it'll hold. just make sure it sticks nicely to the surrounding metal and give it a... **1/8th inch thickness over the hole** ...then to really protect the seal... throw on some black rustoleum making sure the rest of the pan is cleaned with the carbcleaner... overspray slightly.... then if you're really paranoid, which it'll hold... throw on some black gloss that extends past the rustoleum. it'll hold for at least 6 months.
it held an outer brake pad onto my caliper arm, in colorado, for a year n a half.