Vintage McCoy (?) Smiley Face Without The Paint Amazing Condition

This vintage mug is sure to bring a smile to your face. The cheerful yellow color and charming smiley face design make it a perfect addition to your collection of decorative cookware, dinnerware, and serveware. The mug is made of high-quality pottery and has been beautifully painted with a backstamp that adds to its unique charm. I am pretty sure this McCoy based on research and another clearly marked McCoy that I have. However this one does NOT say McCoy. You can see the faint USA on the bottom. No chips or scratches from a clean nonsmoking home.