Wow Laura, thank you so much! The flag looks like an exact match to me. I really appreciate the links to the pages on the Catholic Society and the completed WW1 postcard I had posted to the Translation board a few days ago. It looks like my uncle cut the two sides off the original card, and then glued them together in his old album.
The monument may well have been destroyed or heavily altered after being built. Those photos were just put together on one page of my uncle's old album next to the ones with the flag. The only places he ever really lived/visited that we know of were his birthplace (Ripabottoni) and a suburb of New York City where he settled after immigrating. It's possible that the monument comes from a more populated area near Ripabottoni, some other place in Italy that maybe a friend of his had visited, or even somewhere else for all I know. I just assumed that they were local to Ripabottoni since all his other photos seem to be from that area.