P41 #1:

Rounded pocket and stamped name above pockets indicates post-WW2 issue.  Rounded pocket P41’s are sometimes called “P47”.  Found starched and pressed.

Herringbone twill (HBT) was chosen for its resistance to tearing1, and its ability to prevent rips from spreading2, like a precursor to ripstop that would be common in more recent uniforms.

P41 #2:

Likely used more in the field than #1.  Found starched and pressed.

P44:

Modified for hunting with “poacher’s pocket” on back.

Sources:

  1. US Marine Corps Raider 1942–43
  2. https://www.wwiiimpressions.com/collections/uniform-herringbone-twill-m1941