WW2 Themed Handpainted Pieces of Art

I came across a box lot of these handpainted pieces of artwork related to WW2. They are all done by Ozro Roys of Livermore Falls, Maine. They seem to have some age and I'm guessing they couldn've been done around WW2. I've found records for the Roys online indicating he was Lieutenant and involved in a local gun club in 1914. I haven't seen any of his other work online and I'm not sure about their history or collectability.