Some More Information:
Some research has been done, and the sniper in the image is Corporal Deveraux of Company M, 125th Infantry, 32nd Div - the "Les Terribles." Deveraux was in all of the 32nd Division's engagements. The Division suffered a great many combat casualties. By August, 1918 the 125th was down to half strength.
I never noticed the missing rubber eye piece on the scope. Good observation.
It does look like a bolo scabard, but it's in fact a wire-cutter pouch.