Reb and Yank pictures

I just acquired these from the son of the deceased owner. I remember first seeing these caricatures in the early 60's on postcards etc. The Yank is dated 1957 and the Reb's date is 1961. Both are by J.F. Martin and have a copyright by his name. I have several vintage items with the Old Rebel on them lighters, decals, lapel pin and others. Can anyone give me any information on J.F. Martin? Other prints he made, dates he painted, employer etc. Thanks for looking.

Bill