Anybody successfully repair busted fender-extension studs?

(Regarding the cast ext., not the fiberglass)

My driver's side fender extension is missing two of the mounting studs and the pass. side one is missing three!

As best as I can figure, I've got three options:

• Epoxy some bolts or studs in place.
• Drill and tap the extension where the studs were and use bolts to attach to the fender. (or install studs)
• See if an old co-worker of mine would be able to weld in new studs.

Has anybody here managed a solid repair on their busted extensions? How did you go about it?