Evan - Southern long had access to Middlesboro, via trackage rights from Cumberland Gap through the tunnel to Middlesboro.  As CSXT traffic from Middlesboro dropped off in the 80’s and NS traffic increased, they leased The Middlesboro facility to NS in exchange for NS leasing the Virginian Winding Gulf branch to CSXT beyond Amigo in 1985 (I wrote both agreements).  Having worked on the St. Charles line in the 70’s I always thought that there were similarities between the two operations.  This is the first time that I have seen the 1963 map, however.  It is especially interesting in the trackage that goes past Benedict to Monarch and Imperial.  Sometime before 1970 these two evidently closed, as a portion of the line was retained as tailback room to make the move up into Benedict (the old site).  On my first inspection  trip in 1970 was intrigued by that tailback track disappearing into the woods, and wondered if it at one time went farther,  Now I know.  Thanks.