Hello! I have lived in Sciotoville for a long time. Here is some information about the line.
The line did, indeed, run to Portsmouth. It passed through Sciotoville. It crossed Highland Bend Road, Little Scioto River on a bridge, Bloom Street and Harding Avenue beside what is now Giovanni's (and used to be Hibbett's Hardware).
The last heavy use for the part from Highland Bend to New Boston was in the early 80s. Chessie System would haul coke from New Boston through Sciotoville and then northward through Minford. There is a line that connects to the double main line that runs over the Ohio River. It is a fairly steep grade (probably 3 to 4 percent).
The B&O line was built long before the double main that crosses the Ohio River, which originally started as one line. When the double main was built, a bridge was constructed over the B&O line in Highland Bend. The original B&O line still exists under that bridge and is in use by KSA for loading gondolas with untreated crossties. In fact, up until a few years ago, you could clearly see one or two telegraph poles still standing beside it.
Before the track was removed from Highland Bend to the Knock & Sons Company (just south of Oak Hill), there were several cars that were brought to Sciotoville and left under the bridge (what KSA uses now). There were mostly box cars and tankers (probably 10 or 11 cars total). They must have sat there for a good 7 years before being picked up in the late 80s and taken up to the double main.