The Portland Museum of Art is keeping extended hours Thursday and Saturday for the final week of its record-setting exhibition of Winslow Homer works. Record numbers of museum-goers have viewed the exhibit, Weatherbeaten: Winslow Homer and Maine, since it opened in September. The exhibit, which ends this Sunday, features 38 of Homer’s works that he produced at his studio in Scarborough. Due to the show’s popularity, the museum extended its Thursday and Saturday hours until 8 p.m. through the end of the exhibit while adding an admission surcharge and selling timed tickets. The exhibition showcases masterpieces that Homer created in Scarborough, where he lived from 1883 until his death in 1910.