Two and a half years after more than doubling the size of its Fairfax store after rehabilitation of a vacant supermarket, 44-year-old Good Earth Natural Foods wants to do it again, planning to open a store in the Tam Junction hamlet of Mill Valley about a year from now. If the county of Marin approves the plan to renovate the 26,000-square-foot former Delano's IGA Market in Shoreline Shopping Center at 201-207 Flamingo Dr., Good Earth will transform it with the look and feel of its current Fairfax store.