Steve, you've probably already done this but I'm going to suggest it anyway.
Did you go back and look around on the banks in the area where you think the wind could have carried the tackle box? If it was on Letterman I would bet that a tackle box would float for quite a while. So maybe it blew ashore. Long shot for sure but it could be worth a try.
Ed's right about filing too many claims. Three or four years ago my daughter slid on a wet street and slid over a curb and hit a big landscape rock in a flower bed. It did about $1400 damage to her car. The body shop played with the figures so I only had about $200 out of pocket instead of the $500 deductible but the insurance premium went up over $100 a month for the next 2 years. It would have been much cheaper for me to just paid the 1400 bucks and never told the insurance company about it. My son had a little scrape with another teenage girl a couple of weeks ago. Fortunately, the father of the girl understood my point of view and agreed to let me pay for the damage and keep the insurance company out of it.
If you don't find your stuff let us know. I'll bet most of the several hundred members here at NTOWS could find some crankbait, spinnerbaits, plastics, and terminal tackle that they could do without and send you to help you get your collection started again. I know I've got some stuff I could live without.
Good Luck
Harpo