Wineries damaged by wildfires tearing through Northern California are starting insurance claims, and at least some of the smaller vintners are likely to find limits in their policies mean payouts fall short of rebuilding costs. Gaps in coverage and a spike in rebuilding costs, typical after disaster, may come as a shock to many small wineries, favorites of Napa and Sonoma county tourists, said Tom Pagano, who heads the vineyard insurance practice for insurance broker Aon Plc. (AON.N) ”The easy part of insurance is buildings burning down,” Pagano said, describing the complicated claims process. Crops are covered, but not vines, and policies often impose quirky limits, such as when grapes spoil due to electrical failures instead of fires.