I had more than one of these as a kid. No domes that I recall though...But on one there was a sheet metal lever in a slot by the fire coats and a ramp that when pressed, lifted the ramp and rolled a truck or ambulance out of the door.
The slot was not centered nicely between the table and coats; it always drove my ocd nuts that they didn't take the time to do it "right". I also wished it had two ramps to roll two vehicles out in a "race" to get to a fire.. ah good times 
