Liberty Motor Lang 400 hp.

I have been on a quest for some time regarding the exact aircraft that the Liberty Motor Lang 400 hp. mahogany propeller may have come from. It hangs now in my home high amongst the the beams of our play room. I have been in contact with people from the Smithsonian Institute as well as the Pensacola Museum of Naval Aviation and I have not yet determined the origin. Both parties smugly suggested that it was from one aircraft of another but they were put in their places when I proved to them that it was likely the rear drive propeller from a Curtiss navy NC4 flying boat. This is one of the first aircraft equipped with the Liberty (named after the birth of our country) v12 400 hp. engine. Also the first liquid cooled aircraft motor. Any information that you have would be appreciated.