Your picture is of the Gargraves 5-rail track with the O gauge centered inside the Standard Gauge.
When I get a chance, I will go out to my barn and attempt to find an example of the Gargraves 5-rail track with offset G gauge rails. I will then take a photo and post it.
It would be interested to see this picture, since it might answer my question posted a long time ago:
Above are the photos you requested. As you can see, the O-gauge rails are "slightly offset" to one side inside the Standard Gauge. For display purposes, this offset creates a 5-rail track which supports three gauges, i.e., Standard Gauge, G-gauge, and O-gauge. I used this track exclusively on the shelves I set up in my Vienna, VA home to display my MILWAUKEE ROAD trains. This unique track gave me the flexibility to quickly and easily rearrange my Standard Gauge, G-gauge, and O-gauge Milwaukee Road trains on any shelf in any location.
Occasionally for aesthetic purposes, I needed to change the spacing between the shelves. However, since I was using a "hanging" shelf system, I could easily accomplished this task since the shelves were not fixed to the wall but instead rested on the horizontal "brackets", which were attached at different interval to the vertical "standards", In turn, the standards were hung from the white "track" that was bolted to the wall just below the ceiling (See photo below showing details of how the vertical "standards" hang from the horizontal "track".).
It's difficult to see, but if you look closely at the picture below, on the left side you can just make out the tops of some hanging vertical "standards". As you can see, these vertical standards run down to the floor. Furthermore, at different intervals you can see where horizontal "brackets" are attached to the vertical standards in order to support the 6" oak shelves. Since only the "track" just below the ceiling is bolted to the wall, minimal damage is done to the wall and the entire hanging shelf system can be attached to or removed from the wall in just minutes.
This hanging shelf system is by "elfa" and can be purchased online from The Container Store.