Aside from a different focus, I recall going to something like "East Coast Large Scale Train and Hobby Show" back in the Fort Washington days. (I am pretty certain I don't have the name right, but it was something along those lines - I may have seen an ad over the last few years that this show might still happen, but maybe even at the York County Fairgrounds)
It was a decent display of lots of manufacturers, and I seem to recall it crossed over into some RC stuff as well. Lionel might have been there (this was probably 1999 or so). I seem to recall seeing prototypes for the 15" NYC Passenger set that were made to go with the PA-1 on the cover of the "Classic II" catalog for '97.
I'd imagine the WGH Show to be something more like that than a buyer's meet like York or Allentown.
-Dave
