Thanks for the post. I have been to the Carnegie Science Center a few times years ago when my parents lived in the area. Always enjoyed the layout with the Pittsburgh emphasis.
I also like The Kruger Street Toy & Train Museum in Wheeling, WVA and Oglebay Model Railroad - Wheeling, West Virginia which is O gauge. The Oglebay layout was featured in OGR run 125 in Oct 1992.
The are lots of model layouts near Pittsburgh. I enjoyed the live trains downtown and the incline lift up Mt. Washington.
Charlie