The strength of this image is probably in the idea that a marine who is obviously not from the vietnam era, looks at a memorial that obviously is. So it easily makes one think of the consequence that he might be looking for names of relatives. Of course, he could also just be looking at the extraordinary paint job. So that would be a slight minus: there is no emotion visible. He is not pointing at the names, intensely reading them oss.
What also struck me is that the original crop does not reveal any hints on the nature of the memorial. This makes the memorial look weird. It is on the side of a car, but that doesn't show. The original uncropped image reveals part of a wheel in typical dragster style, which immediately makes it all clear. It hints at the context and does so splendidly. So I would definitely add that extra bit.
Lastly I don't understand the background clutter crop. Background clutter is not an argument to crop, composition is. If you need to obscure background clutter, the photographer has a tool at his/her disposal which is specific to photography: namely background blur. And in this case, given that the background is more than several yards away, there is simply no excuse not using it. Sure in the spur of the moment one may have missed it, but that probably means a missed opportunity. The composition does look more balanced imo with the wheel included, and the shape of the tail visible...
(In that regard I also do not like the slight unsharpness in the elbow, while the unwanted background is tacksharp. It should have been the other way around, which adds to the intimacy of the scene... )
The image does look better in B&W. The image screams B&W. It helps tamper the distracting elements. I do not think it needs sepia. For illustrative purposes: