Sonoma Developer Ken Mattson is facing more defaults and possible auctions of his properties. The Press Democrat reports that KS Mattson Properties has received at least 13 default notices since June 28, representing up to 19 different addresses in and around the city of Sonoma. In addition, nearly a dozen of Mattson’s properties are scheduled to go up for public auction in August if mortgage payments aren’t brought up to date or an agreement reached with lenders. The properties involved are mostly residential homes but also include the Cottage Inn & Spa, an Inn to Remember, office buildings, apartments or condominiums, a warehouse and a small shopping center.