It looks like that, if you would take it down to two tracks from three, there would be enough clearance. Maybe you could cut some stuff off the deck so you could flip it and have it fit flat on the float. That would give you a smoother surface to lay new track.
The tower has plenty of overhead clearance. It doesn't look like there is enough side clearance along the outside rails on the apron so you would probably have to make your own deck for that.

The picture is from here:
http://cs.trains.com/mrr/f/11/t/132444.aspx