The family that owns Don’s Lunch Van, a popular Westbrook eatery shut down Wednesday for nonpayment of state sales taxes, says it hopes to reopen the Main Street business. But whether that is possible is still unclear, said Justin Richards, a family spokesman. “Right now we are weighing all of our options and trying to figure out what is the most feasible route to take,” Richards said Saturday. Richards’ grandparents, Don and Yvonne Richards, opened the business in 1976 and sold it in 2001.