I realize this rifle looks like a TN gun, but there is a good chance it was made in southeastern Kentucky in the Cumberland Plateau or "hill country" region. The slenderness of the rifle, length of barrel, tight side facings, and iron furniture were all used in a couple of counties in that area, close to the Tennessee line. The cheekpiece is also similar to several maker's work from that region. I cannot find a maker who lines up with the initials, but unfortunately we know less about gunmaking in that area of Kentucky than any other area of the State, so there is still work to be done. Fewer records and less information is available in those counties due to their reduced populations, backwoods ways, and most gunsmiths being recorded as "blacksmiths" since that's where they spent most of their time. The last two letters of the barrel marking may well refer to the county the gun was made in, i.e. "LE CO" despite the final "O" not being completely closed. If so, Leslie County, and more likely Letcher County, are where I would look in KY for the gunmaker.
I also think there is a good possibility the original nose cap is gone, perhaps from a slight shortening of the barrel, and we are looking at a cast replacement cap on this rifle. The current nose cap doesn't seem to "match up" in fit & finish with the quality of the other iron furniture or the rifle in general, which is a beautiful piece. Shelby Gallien