PHILADELPHIA — Have you ever seen a piece of art and thought, “I could totally do that — and better”? That’s what David Morgenstern realized when searching for pumpkin carving inspiration online 16 years ago. Now, Morganstern runs Stoneykins, where he sells custom-made intricate jack o’lanterns and design stencils, while also running a Facebook hotline to answer pumpkin carving questions. Morgenstern, who attended the Art Institute of Philadelphia, hails from South Philly. He is winner of the 2013 Pumpkin Masters Online Carving contest and the 2021 Great Pumpkin Carve in Chadds Ford. He’s know…