This is the original preliminary artwork created for a novel clearly associated with WWII: two men, one a Japanese airman and the other an American soldier, look to be squaring off while the likely target of their focus is the battelship below.  Neither the Sweet estate nor I have been able to provenance the title of the book...there are very light notations in pencil along the top edge which point to publication; if you can identify it, please let me know!    Great visual effect, in acrylic on gessoed illustration board, 7.5" x 4.75.  There is no info on the back; if you would like a letter attesting to authenticity, happy to provide it.