A Quite Evening at the Gunpit

Five members of the mortar squad are spending the evening setting up H&I's (Harassment and Interjection fire).
The Marine on the right is sitting on top of the ammo bunker while another is kneeling at the gun, probably sighting it in.
Three others are in the pit preparing rounds for firing.

The four red & white striped aiming stakes for the mortar are clearly visible in this photo.
The Vu Gia river is in the background at the base of the mountains.

If you know anyone in this photo or their whereabouts
OR
you are in this photo, please