Several years ago Classic Toy Trains published a track plan based on a 1950s Lionel layout. It was in a supliment packaged with the monthly issue. It took the L shaped original and splayed it out as a flattened V shape by cutting off one corner and reattaching it to form the V. I lost my copy of the track plan and would greatly appreciate any help to obtain a copy.
The Long Island Railroad museum in Riverhead NY has just made public the Lionel Corporation's layout which was donated to them by Lionel. 14' x 40', it is based on the original 1950 layout that was in the Lionel showroom. You can try contacting them to see if they have a track plan available. If you google them, you should be able to find lots of pictures of the layout.
johnda- Welcome to TrainBoard! Does that museum by chance have a web site? Do you know of any pictures? I'd love to see a few views... Boxcab E50