Thank you, elh1311.   I actually found the thread you are talking about late last night.    And you are right; it is a very informative deep dive on the matter. I think my questions have been answered!   I appreciate your help.   Bryan.

There's a great thread on here that deep dives the topic. You'd have to search for it but it is informative. 

Here is a link to an auction of a non-marked Firmin TO wing   https://www.ima-usa.com/products/original-u-s-wwii-aaf-scarce-british-made-sterling-silver-technical-observer-wings-attributed-to-firmin-pinback?variant=43319751966789

Also, WW2 era blues will not have size tags. These, also were paper tags. Paper tags were just tacked in at their corners. Any tags like this were always removed. 

Tags!  Forgot about tags. You won’t find tags in dungarees, (pre 1980, Navy issue), or whites, (same caveat as dungarees). All those tags were paper. All paper tags are removed when you get them.   

Based on the T closure, this could be one of the postwar Norwegian pistol belts that someone has added USMC markings to.

Jerry_k,  Thank you for the link to a fantastic thread on the very question I was seeking answers to.  Yes, I missed that one entirely, perhaps as I used the term 'Dungarees' and not 'Denims'.  Posting #101 on that thread is exactly the pattern of denims that I have.  Upon a more intense inspection I can see where the contract tag was removed, thus no precise date of manufacture can be determined.  As I primarily collect post Vietnam era women's uniforms, this has been quite the learning experience.  I will add 'denim' to my vocabulary when seeking information on Navy working uniforms.  Cheers, Armygas

Sigsaye, Thank you for the detailed reply and context of why and when an "O" would wear a 'dirty work' uniform.  ""Yrs, those are navy issue. There were several different patterns of dungarees, that were used simultaneously.""  I can relate to working on old cars and how dirty the job can be.  Thankfully most of my time in the Army was in camies that were great for hiding the dirt and oil stains.  I have read hundreds of your postings and found them to be a fountain of first hand, real world, US Navy experience.  All of which has helped greatly in understanding how uniforms were worn and the details such as the halyard clips for keys were used.  In the Army we used carabiners for the same purpose.  Again, thanks for your reply and insight.  Cheers Armygas

Always need to post photos of the reverse.  

Thanks a lot