I just don't know where to go with this.  It is a toughie for sure!  The unfortunate thing with the damage on this is there is no easy way to repair it without altering the original appearance of the cap or replacing significant amounts of original material.  If I were going to attempt any repair, I would try to stitch the separation closed…tacking it first and then carefully stitching the separation from the inside or outside if I was unable to easily access the interior.  My concern is that looking at the condition of the cap I am worried that any stitch would simply pull through what appears to be rather dry-rotted looking material and this is an area where the stitching really needs to be tight to achieve the proper look thus exacerbating the problem.   If this cap is something extremely special in your collection (i.e. family piece or id'd/part of a grouping etc.) I'd leave it just as it is.  If not, I would consider leaving it as a place holder until something  better comes along.   I am in no way disparaging this hat...it is what it is and it has survived to this day!  I am just letting you know my opinion as someone who has repaired numerous visor caps over the years.  

Alamo City Militaria Expo Knights of Columbus Mikulski Hall 509 Schertz Parkway Schertz Texas 78154   https://www.acmemilexpo.com/show-info.html   General Admission - $5.00 Kids 12 and under - FREE   Free Parking!   Food and Drink available on site. ATM available on site.

By far "Johnny Got His Gun" (1938).    Highly recommend reading.    Wade

West Coast? Philadelphia, PA has a Market St.

Thanks for the information! 😀 I'm currently doing some research trying to see if I can find who this mystery service man was!! 🧐🤔 Lol     

Robin-  Sounds like a cool event in a cool small town!  I'd love to attend, but it's just a bit out of my neck of the woods!  Hope you do well and enjoy yourself.       Steve

USAF / 19th Bomb Group (Medium) b/w 28th Bomb Squadron (M). Kadena AB, Okinawa. B-29 "Superfortress". Korean War. Japanese-made "Prince" featuring the always desirable "Attractive Chrome Finish".

aznation--No, nothing posted yet, I hope to get photos taken soon but seem so busy right now with outside projects to do--yard, garden etc. , etc.!. Hope to start soon though!                   Thanks     Steve

Armygas-  Thanks for the additional photos of what they made for the U.S. services.  A good variety of metal containers for sure.     Steve

Beautiful cap. A privately made version of the Army's 1902-1911 pattern dress cap for enlisted men. Its less usual to see these with a west coast uniform companies mark. These were typically bought by state National Guard soldiers, occasionally Army NCO's putting together a tailored uniform, recent veterans and etc.