The beauty of the cantiliever is that you can still get under it since there are no legs. It's a lightweight table and would give you more operating surface for those long straight areas. It you think about how much you can put in a 24 inch module as compared to a 15 inch one, you could put a lot of action in to it. If you wanted to simply add the girders without taking up track, just cut what appear to be one by fours and lay them in side by side next to the existing ones and screw them sideways. Just make them longer. Does that make sense?
I am south of North Conway in Chocorua, a hamlet near Tamworth. The tree farm has been in my wife's family for about 200 years.
I also know a guy who has tons of Maine Trains. Maine Central, Bangor @ Aaroostock, Boston and Maine, Guilford... He used to have a shop in Kezar Falls but moved to AZ. He will be selling via internet in the near future. I can get you his email. He had me expanding into the Santa Fe and Bangor Western. We have killer trackage rights.
If you go to the show, I'm going on Saturday. I'm the old guy with the Gray ponytail. It tends to stand out. We could meet up.