My memory is off. 1948 is not stamped into the sheath. The nomenclature starts is NO. 48C3639. A1 Machette and sheath. This one is stamped on with ink. others have the same info stamped into the leather   Check out the link...    

Yep understood, however having said that, some aviators uniforms, though in the minority, are made from cheaper heavier wool. Like all officers, they had to buy their own and no doubt some were less expensive for those pockets not so deep. 

Just found these buttons. Probably a civilian blazer button.  

Here's an example, the 107th Infantry PP 107th Infantry in the 42nd Infantry Division New York New York, which makes it depending on the year this shirt was worn, 1st Battle Group 107th Infantry in the late 50s early 60s, or after 1963 either the 1st or 2nd Battalions 107th Infantry. Note the wear above the U.S. ARMY Tape, something unique to all the units of the New York National Guard in the 50s into the 80s.   The 104th Artillery by the way was in the old 27th Armored Division  by 1960, its 1st Battalion, it was assigned sometime in the late 1950s with the PENTOMIC Restructure, before that it was in the 42nd Infantry Division of the NYNG, battalion now consisting of the 1st and 2nd Battalions, the 2nd Battalion stays with theb42nd Div, the 1st goes to the 27th Armd Div. so this 104th Arty PP could of been worn on a 42nd Div shirt pre 1959 or post 59 on a 27th Armd Div shirt.

Naval aviators were officers (and warrants) so they were supposed to wear the officer version, yes.  ^https://www.history.navy.mil/content/history/nhhc/our-collections/photography/numerical-list-of-images/nhhc-series/nh-series/NH-52000/NH-52844.html  

Yup. Its converted into an old shoe shine box.

I read that the navy had these Blue Cammos because they hid dirt and grease.

I dont have it yet but they do appear embroidered. Ive never seen the sailing ship with the eagle and anchor?

The ones I have all come in a tan leather sheath and have a date of 1948 stamped on the sheath.

I have made my own DIY one and it works fine for my purposes. Looks decent as well. My “war room” is a work in progress