Awww, the Joe Long that's probably not a Joe Long, but a nice rifle anyway and made up in that same area.
As for the marks, the guy was more or less correct in that it just a flourish mark that some makers put between his first and last name. Some of these marks have become very well known to collectors, like Dickerts tomahawk and arrow cartouche.
Sometimes if the maker name isn't very legible for some reason, the mark can help in identifying the maker. These marks are generally between the first and last name of the maker on the top of the barrel, and shouldn't be confused with a barrel makers mark which is generally on a lower barrel flat back close to the breech.
Sorry your question got overlooked.... maybe everyone's out enjoying the nice weather
John