Photos like this tell a great story - a story of remembering veterans, despite them participating in wars that our generation might consider quixotic or misguided. That, and being able to honor those who served in the defense of their homeland, is extremely poignant.
The duotone looks good and there's nice detail here. I kinda wish the tombstone had more impact since as it stands now the trees carry most of the focus and real estate.
Good shot here. Your choice of framing and composition, with the grave filling the foreground, and including the trees, and other stones in the background gives a good sense of depth to the image. Maybe just a matter of taste, but I might try to adjust levels just a bit, and try to bring out just a tiny bit more darks in the grave and grass, just to give a little boost to the overall tonal range. Nice job.