U.S. muskets and full length service rifles had the rear sling swivel on the trigger guard for decades, from the earliest days through the trapdoor Springfield. It was not until the 1892 Krag that the swivel was moved to the bottom of the buttstock where we are now used to seeing it.
Hi, Mr. Lahey,
Changing the photos on photobucket won't change what the server on the site already has, but no problem. The original finish was what was called "national armory bright", in other words, bare metal. That finish, given time, handling, oil and just sitting, will turn into what is called in the antique trade, patina. While basically rust (as is bluing), smooth brown patina is a pleasing finish and most collectors will advise leaving it alone since it is not active rust. As we saw, it can look blue or black in photos. The presence of a nice patina instead of a modern blue job would add several hundred dollars to the value of the gun.