[dutchmensport]

My very first thought after reading your post was identical to #2 option above. Cut a small hole so you can see inside, attach the handle, and then use foamy 'Stuff" expanding foam to fill the hole.

Tip, every time you touch the handle, turn it clockwise. If it's loose, you will always be tightening it up. If it is already tight, it won't turn any more, but you are keeping it snug. Don't over turn and break it, just turn the handle enough to make sure it's snug. If you do this, it will never come off again.

I had the same thing happen to one of my prior travel trailers, so I'm talking from the same experience here.