The common marking you find was the owner's name and Army Serial Number.
Edward J. Adams - 12246718
NARA - AAD - Display Full Records - Electronic Army Serial Number Merged File, ca. 1938 - 1946 (Enlistment Records)
Thank you so much
Ed is correct. E.J. Adams was the soldier who was issued these items and the number is his army serial number.
Soldier's were given equipment based on whatever was available. They could have been given gear from all the same year/ manufacturer or a mix of everything. If old gear/ uniforms were all that was available (for example, from World War I), it's not uncommon for that stuff to be issued too.