Vintage circa 1940s British cotton drill army smock/ pullover jacket.
 
No size label on this- there is a War Department broadarrow stamp inside stamped O which indicates that it dates from 1942
 
Most likely made overseas, this style was issued to the King's Africa Rifles regiment. 
 
All cotton, a khaki drill with change buttons to fasten which look to be more recent replacements. Inner side pocket, epaulettes, side slits. 
 
Being sold "as is"- showing repairs and small holes at the chest pocket and a large overstitched repair at the back.  Some general surface wear. There are some rust type marks and stains at the upper arm, at the side slit  and around the back of the neckline,  a few here and there.  
 
This is a military piece constructed like workwear. Laundered.
 
Seam to seam across the shoulders at the back is 17 1/4"
Sleeves are 24 1/4" from shoulder seam to sleeve end
Total back length is 26"
Across the chest under the arms is 22 1/2" - pit to pit, flat, across the front measured flat
24 1/2" side to side across the hem (there are side slits so there's a bit of give in this).