Its flint because it was made for the export market in some less developed part of the world, most likely Africa or the Middle East. The Liege trade was still turning out various grades of these doubles, none of them all that good, well into the 20th century. Not all of the Belgian export guns were the junk that Dixie and others were selling back in the 60s but they aren't what would be considered European market quality either. There is much more emphasis on "fancy" than there is on function. If you look at the reprint of the 1911 ALFA catalog, they are even show there.