Shirt: german military uniform issue olive drab fritz and sohn 39/40 Used

Label: fritz + sohn polyester q/b54a/b0043/bd828 11/81 3-39/40 8415-12-178-3472 39/40 is a med or sm lg Bought used but in acceptable shape. I have no idea when this was made. Maybe it is 11/1981? I can’t find anything like it online. I can tell it is German and the size/material, but that is it. Shirt has no stains or holes, but has some pilling on front and collar. None thick soft shirt! Armpit to armpit: 22” Shoulder to bottom: 27.5” Sleeve cuff to shoulder stitching: 22”