The EBT did run the asphalt tankers to Robertsdale, but they had to be careful. As one story goes, one got its dome torn off in Wray's Hill Tunnel because they did not fill it with water on the return trip to weigh down the springs. The photo mentioned of a tanker cap being removed was in "East Broad Top - To the Mines and Back" p. 14. There are also reports that they sometimes had to jack up the overpass bridge at McMullen's summit to clear certain cars.
The adapters had a top section covering the knuckle of the standard gauge cars that allowed it to hang on it.
The other bid standard gauge traffic was covered hoppers of concrete headed for the turnpike construction south of Neelyton.