I bourght this on ebay a couple of weeks ago. From what i can see is the shell maybe a Vietnam era and is front seam. And the liner is maybe WW2? I have no idea really, there is something marked on the webbing of the liner, but i cant make out what it is. And the liner is stamped "W" and the number 104 above the Westinghouse stamp.
Check out the pics, and let me know if you very wise men have some info for me