MYRTLE CREEK — When he wasn’t on the playing field at South Umpqua High School, Jeff Johnson could be found in the lumber yard at Del’s Building Supply. The teenager, as a part-time worker for three years, made a good impression on Dick and Shirley Petterson, the owners of the supply business. The teen also house sat for the Pettersons when they were out of town. Then several years later, when the Pettersons were looking to retire, they mentioned the possibility of selling the business to Johnson. “I came by to visit, and Dick said, ‘Why don’t you buy this …