Working out a couple of ideas: 1) have the On30 do something useful: industries off of the oval generate ore and timber, which cross over the O mains to the other end of the layout, and are transloaded to the 3R O-gauge. The O-gauge at that end of the line, has a mine.
2) re-align the staging at the bottom, partially hidden, a connection to another RR and an interchange track.