Jeff, sorry, but can't double your space 
and I don't think a runaround siding will fit, the tracks there are too close. What I did was steal some space in the lower left, if Mike agrees, and added an escape track to one of the slots in the yard. I also added a parking track in the upper left for a yard switcher.
FWIW, the upper level is simply to give the layout some height, room for a raised town or industry and maybe a mountain scene.
