Lease of Mullet Key buildings to Percy Roberts was ratified Monday by county commissioners who made no change in the tentative lease approved last week.Roberts will pay the county $50 a month for the first year and $100 a month for the next two years for the lease of two buildings on the extreme south end of the county's property on the key.The lessee will operate a daily boat service to the island and will serve fish dinners and rent fishing tackle. The distance from his dock near the Bee Line ferry will be 10 miles. He will land in a sheltered cove on the north end of the island. Trips will be started in about three weeks.