Mike,

That one had Belgian proof marks. The Belgians sold a lot of guns in South America. The .44WCF aka .44-40 was a very popular round.

There has been some discussion about the .44XL, the American pre-cursor to the .410. I have never seen a .44 Largo. I will have to keep an eye out.
http://www.doublegunshop.com/forums/ubbt...true#Post137257

http://www.doublegunshop.com/forums/ubbt...df792#Post20243

Pete