Vintage Waxed Canvas Messenger Bag Field Bag Satchel Black Postal? Military?

This is a rare one!!  We couldn't find too much on this particular bag as there was no markings we couldn't find.  Features a waxed canvas shell with a leather adjustable strap.  Buckle & slide flap front compartment  Same strap style main compartment with two outer pockets  Vintage Eagle Brass style Button front ( only button)  Our best guess is possibly early 1940s/50s postal carrier bag? Or possibly even earlier military? We can't say for certain. If you know or have any info for us feel free to let us know!  Condition Notes-  In good shape especially for its age. Has minor marks and normal signs of use/wear mostly around the edges.  All hardware works and is fully functional  Questions? Don't hesitate to reach out!  Why shop with us?  We know you have many choices, and we work hard to provide a better buying experience:  Fast shipping: ~ Orders ship the same day or by the next business day.  10,000+ happy customers worldwide:~Join our growing community of returning buyers.  Quality brands at great prices:~ Find products you know and trust without the high markup.  Carefully inspected items:~ We check every item and clearly disclose any imperfections.  Stellar customer service: ~ We're happy to help with questions, concerns, or special requests.  **Save on shipping!**  Purchase multiple items and enjoy free shipping on additional purchases~ when eligible.  Message us for details!