Have you tried City Hall at MK?
For our honeymoon back in 2000, DH lost his wedding ring (first day of our honeymoon!) on Splash Mountain! We knew exactly where it came off and the Spash CM's had us report it to City Hall. City Hall said they would call us if it was found and if we didn't receive a call to call central lost and found, which I'm sure is where you called first. Central never called us. We called Central and they didn't have it so DH called City Hall the next day and they had it. good luck!