I have tried to solve this riddle with no luck. If the handle is in good condition but very loose, Ive used a hacksaw to cut the aluminum rivets, then reattached the handle using a nut/bolt. Its worked great and results in a solid handle. The trick is to find the right length bolt and countersink the nuts in the bottom handle so you don't feel them. I usually use a drill bit turned by hand to enlarge the holes since its very easy to overdrill through the handle.