Never been, but here is some vendor info from the Precision Museum's website..... Some of these guys I know quite well from Cabin Fever and Rough & Tumble Engineers...the others I took an educated guess.
Richard Sabol and Laurie Olson-Sabol, Dover NH - custom artwork shirts and rubber stamps (nice stuff)
New England Brass and Tool Inc., Winchester MA - ? I'd guess tools and bar materials
Peter A. Renzetti, West Chester PA - handmade miniature welded figures, some Stuart parts, machine tools, custom machine work. (a nice gentleman)
Paul McDaniel, Amherst MA - ?
Andy Lofquist, Metal Lathe Accessories, Pine Grove Mills PA - ? sounds like machine tools and accessories
Centerport Cycles inc, Northport NY www.centerportcycles.com - ? custom bicycles judging by their website.
Nation Builder Books, Leesburg VA www.nbbooks.com - all kinds of books on everything from colonial life to the space shuttle, architecture, blacksmithing, railroads, antique tractors, machining, even cookbooks...(plus Tony is a super cool guy.)
some highlights from the 2005 show http://www.scaleautoworks.com/VTModelEngineeringShow.html http://www.americanprecision.org/Model-Engineering-Shows/6th-annual-Model-Engineering-Show.html