I am the curator of the museum of Stan Appenzeller in Seillans, France. We have some portraits of soldiers in the collection and I don't know the name of these persons. Perhaps somebody can help me. I am not sure that is Général Klemens Rudnicki. Stan was Etienne in the french/polnish reseau S2 from 1940 to 1947. It seems that Stan is from back on the photo withe the king. You can see the website of Stan : www://stanapenzeller.jimdo.com
Stan was a great painter before and after the war, and we have more than 900 paintings of him.