What later became the Norfolk and Western line from Cincinnati to Portsmouth was originally NG before become SG.
That line goes through my home town in Clermont County. Part of the Cincinnati, Georgetown, and Portsmouth(Which never made it to Portsmouth), was NG as well.
Dave McNeil did a nice book called "Railroad with Three Gauges". I helped him one long day find a few spots that he needed to find. Most interurban in these areas,
and to this day I believe there are 2-3 interurban bodies that are attached to dwellings within 30-45 minutes of here. A giveaway is the arched window frames.
Greg Scholl