British?

This is the third I have come across over here in the past couple of months by two different sellers, both sellers are insistent that they are real.    To me it looks like somebody has clipped the clutch back pins off and changed it to a pin back.     

Thank you Salvage Sailor. The first link doesn't seem to work though.

There were many Mexicans who were citizens.

Brilliant, thanks! A very interesting photograph. Compared to the Navy and Marines, the Army didn't offload regularly like this, otherwise the lifting rings would have been adopted as standard I guess?! Cheers

Ok, I think it may be a Patch King railway artillery reserve patch based on a search but if someone has a different idea let me know.  I don't know why it's stated as a "Patch King" patch though. https://www.usmilitariaforum.com/forums/index.php?/topic/8082-railway-artillery-reserves/

There was an interesting World War I uniform at the show that had a patch on it.  I’ve never seen anything like it before. Maybe someone else on the forum might know what it is.  It’s that patch under the big A that I don’t know what it is.

Yes, my uncertainty does regard what an earliest date could be, comproved by any references (period pictures, or something) of actual service for the A-10 (R) in overseas units. This 'cause should it turn out being a too late time, that pulls my future display beyond the acceptable timeframe in wich I can assemble the aviator without the AN-R-2 raft case attached to the AN-6510 'chute.  Date of 4-1943 as molded into the rubber of this specimen isn't an issue if anyone could comprove the A-10R was already seeing service in February-March 1943, that's not important to me. Sweeting's book cites this variant as 'standardized in late 1942', yet I cannot find any official reference prior to February 5th, 1943 when Technical Order 03-50B-1 came into effect.   If I can find out any comprovation of the A-10R being in service out there in very early 1943 I'll put it on the character, but if not the case I'll do without it   -    in fact the guy will be a P-39 pilot of 68th Fighter Squadron flying from Kukum Field at Guadalcanal and I'm guessing in most of those missions, oxygen wasn't needed. 

I don't really have any answers to your specific questions but I believe the writing inside the cap on one side might be C. W. Seiberling, Seiberling Rubber Co, Akron, OH.  There is a Charles Willard Seiberling and a Charles Willard Seiberling Jr.  For more info on the Seiberling Rubber Company see here =>  https://en.wikipedia.org/wiki/Seiberling_Rubber_Company   On the other side of the cap I believe that to be Wm (William) E Holler out of Detroit, MI.  William E Holler was a major car salesman/dealer in the Detroit, MI area.   Why these two people names are inside the cap is anybody's guess but both seem to be automotive related.

With his full name, I confirmed his dob and dod at Find a Grave (I could not make out your headstone photo), then went to Ancestry. That provided the Headstone Application with his correct service number. I used that to find his enlistment record, etc. Without that application, it would have been more of a challenge. As I said earlier, I could not locate his PH orders (at the regimental level); the 91st ID did not not issue PH orders at the division level, as best I can tell, so maybe his were issued by a medical facility. I tried both his name and service number, but could not locate a hospital card for him either.