Featured Kingdom of Italy Flag

My Dad acquired this flag around 1975.
The seller claimed it was taken from the Battle of Monte Cassino by a US soldier.
Dad gave it to me, so I am curious if the story could be true. My research tells me that this design was used 1861-1946. I'm wondering about the vertical orientation, and if this was indeed from that time period and place.
It measures 55x31" (139x78cm)
Any info is greatly appreciated!

 

Given it's orientation, it's a banner, not a flag. No reason it wouldn't be genuine period. Assume the Monte Cassino part is battle of and not the abbey itself.

Debora

 

You might be able to get the flag authenticated, but you'll never be able to prove a Monte Cassino connection. Not to say it couldn't be true, but how could it possibly be verified?

 

@Debora
Yes, a banner of course. Dad had it hanging on the wall when I was a kid, so I've always been curious about it.

@moreotherstuff Yeah, that's what I figured. There's really no way to know, but I was hopeful it was genuine WWII, at least.