WW1 US Army 'Doughboy' cotton tunic, with overseas service insignia, small

A WW1 US Army cotton drill service tunic, with two gold chevrons each representing six months of overseas service, plus the faded red honourable discharge chevron that signified the transition to civilian life and allowed the bearer to continue to wear the jacket in civvy life without the need to salute officers. It also bears the collar badge of the medical corps. It's in great condition consdering it's over 100 years old, couple of small holes in thr right sleeve and some fraying at collar edges. It's pretty small, please check measurements:

Pit to pit 19"

Shoulders 17"

Sleeves 23.5"

Length at back 27"