Officials at Pacific Lutheran University recently sold at auction an abandoned painting, netting about $400,000 for the school’s Scandinavian Cultural Center.   But before they could sell the painting, they checked with Bill Holt.   The painting’s last legal owner had disappeared 90 years before, and the painting had been in the care of related family members for decades.   The most recent holder gave the painting to the University a number of years ago.   The question arose, could the school guarantee ownership to a buyer?   Holt found a state statute that allowed the school to sell the painting after first publishing notice of the sale in a local newspaper.   The proceeds from the sale will benefit activities, exhibits, scholarships and the study of Scandinavian culture.