The buttons are from after the Civil War, perhaps for use by veterans. I also tend to think the guidon was put together as a prop for the display. I don't see a star with the number 32 simply cut into the fabric holding up under real campaign use. But just my opinion, maybe a real flag expert will come along.

Addendum...   My dad worked for a major airline that went bankrupt right after my freshman year in undergraduate college.  He was able to retire with a pension.  My future, at that point, was super-extra uncertain, and not looking positive.   I applied for an Army ROTC scholarship and got turned down!    So...  The Air Force took me instead (AFROTC scholarship).  It enabled me to finish undergraduate college AND complete two graduate degrees, while I was on active duty.  Education was my angle.  I got a second chance and then some!  God knows what would have happened if I'd had to drop out of undergraduate college due to lack of finances.  I'd have ended up like "Winger" in "Stripes".

If you're having no luck with finding a potential match with the 11th armored try taking a look at 103rd ID rosters, they also did rank on the sides of their helmets. There are some period photos and attributed examples of the 103rd in this thread I found when researching one of my helmets.  

Funny, I just took this picture regarding wood grips before I saw this post, but here's the same on my 1917 SA missing the guard, so probably fairly common during a certain time period. 

Tell me this isn't SOME of you...   True...  The military does believe in second chances, even if life doesn't...   By the way...  U.S. Army 250th Anniversary to-day!  Thanks to ALL soldiers, in peace and war!     The March From _Stripes_.mp3 Stripes March - Elmer Bernstein arranged by David Swenson.mp3 Winger.mp3

Here's a set of Italian on a US 1917 SA missing the guard. 

I picked up some of the sarco ones a few years ago and they didn't even fit. One of these days I'll probably modify them.. I've used some surplus Italian wood ones. They're smooth and the later style that are thinner on the bottom, but look nice. 

My guess is some kind of cav modification.

Yard sailing w/ wife & sister-in law last weekend ( ahhh) found 1914 Mills 10 pocket  pucker pouch Has 2  approx 1 " round mushroom shaped brass buttons at top  and 1/4" pointed brass studs in bottom middle each pouch What are these for? Thanks