In the book, "Colonial Frontier Guns" by T. M. Hamilton, he documents a Left Hand Fusil Fin in Figure 33, Page 60 and 61. The left hand fusil fin was found in a grave on the Louisiana State Penal Farm at Angola. He documents the other articles were found with many other burial objects.
The parts were quite decomposed but the bore may have been 0.625". The lock was unbridled. The side plate was brass along with the rampipes.
Hamilton is of the opinion that "this is the only left-handed 18th Century gun to be recovered archaeologically."