Why dont you knock on the door and ask the owner. If they are not interested in selling to you now, give them your information so that they can contact you if they ever decided to do so. If you are not comfortable knocking on the door, mail them a letter.
I am an agent in Westerly. If you send me your e-mail address I would be happy to contact you if this home goes on the market. I see from the town card that it was last sold in September 2004, is this the correct home? I would be happy to do a free market appraisal of the home as well.