Good for you and I hope that you are successful in getting the ring back to it's rightful owner. They will be THRILLED that you have gone to these lengths to do the right thing. The world needs more people like you.
I would call the school at 561 243-1500 and hopefully they can go back to the 1991 soccer team and find a Kelly with the initials KMK.
Best of luck!!!!
Always at Your Service,
Tom Priester e-PRO
"Results Driven Real Estate"
Keller Williams Realty
Next best thing is to contact the school directly and let them know what you've found. If you want to get creative, post it on craigslist.org under their 'lost and found' section. I left my camera on the back seat of a Yellow Cab in NYC last month and someone found it and returned it to me within 3 days. 12 million people and I got a person JUST LIKE YOU!
Scott Miller, Realty Associates, Boca Raton, FL