Fixing "ears" on an Arri fresnel?
 

One of my Arri 300's has a loose ear. (one of the two the metal side flanges that hold the barn doors on the front of the instrument - the bottom and the swivel top flange are fine) It's rivited and I've tried to use a die punch and hammer to re-secure it, but I'm having trouble getting it to hold.

Anyone ever delt with this before and found a reasonable cure or do I have to send it back to Arri to have them re-rivit it?

(I don't have the time or inclination to take the whole instrument apart to re-rivit it myself.)

TIA for any help.