I have a Harpers Ferry model 1816 conversion in excellent shape. The lock is dated Harpers Ferry 1816 with eagle forward of hammer. It has a natural overall brown patina consistant with a gun that is almost 200 years old. The finishes of the metal and the stock have not been messed with. The rear sling loop is forward of the trigger guard. Can anybody tell me why there is no bayonet lug nor a forward sling loop?. Looking very closley at the top of the end of the barrel, I can detect where a lug was once by the shinnier area in the shape of a lug in contrast to the brown patina. Also, under the front barrel band it looks like a skilled gunsmith has removed the sling loop.