Manufactured by So Sew Styles Inc.

Marked a vintage military Medium Regular.  Please check the below measurements for an indication of sizing. This is 24" pit to pit.
Best to compare against something which already fits you well.

All cotton outer shell. Rollaway cotton hood with RAPID zip pull. Plain brass "paper clip" tag zipper to fasten. Popper fastening pockets at the front, velcro tabbed cuffs and chin strap. Army badge above the chest pocket and patch on the arm.  Lined in cotton with a waist height inner drawstring. 

Surface marks here and there- some mottled stains and patina.  Some fray ladders, marks and some small holes at the front placket.  Some stains in the lining towards the hem and at the front edge- see photos.  Some fray nicks here and there, a few small holes.  Some marks here and there and general wear. 

DO NOTE THAT THIS IS MUSTY/ STALE SMELLING FROM STORAGE AND NEEDS TO BE LAUNDERED BEFORE WEAR.

20" across the shoulders seam to seam
Sleeves are 26 1/2" from shoulder to the end of the sleeve, in total
From nape to hem is 30 1/2"
24" across the chest under the arms, the same across the back, measured flat, side to side, pit to pit