You crack me up, Dan!
Maybe a few detials from a DC resident and former Smithsonain intern (me) will shed some light. I think the hydraulic monkey business was as much for the sake of the Arts and Industries building as for the engine. It's the second-oldest building in the Smithsonian complex and a historic landmark in its own right. Have a look at those marble floors in the photos-- and then realize that around them are cast-iron columns, filigree, and all sorts of doo-dads. Not the place to try to maneuver a semi-trailer or even heavy cribbing and beams.
Similar issues on the other end-- the door to the Railroad Hall in the Museum of History and Technology is located at the basement level at the bottom of a farily steep grassy bowl. Making things worse, the display tracks inside the hall run perpendicular to the avenue of apprach down the grassy lawn. So, you have to get the engine off the tilted trailer, and then get it in and rotate it 90 degrees within a very confined space, all without scratching the pretty green on 1401.
So the sum total: an hour or two to cart the thing across the mall, but a buch of days maneuvering it out of and into buildings which are a lot more cramped, fragile and confined than the average train shed or roundhouse lead.
PS--love the Eureka. Never had the pleasure of seeing it in person, but the Pentrex video of you on the D&S is one of a handful thant I have bought--normally I'm a books-and-still-pictures kinda guy.