One of the (many) reasons that has me convinced you're completely full of bull**** is that to undertake a project such as this roundhouse restoration that you keep insisting is a go, you must be resourceful and pro-active, which you clearly are not. Instead of getting all of us to do your research for you, a resourceful you would have already found the answers to your gazillion questions. For example, the first thing you should have done when coming to this web site was to use the search engine and type in the word "Manchester". You would have then known that there were two cabeese awaiting display just down the street from the round house, and you would also know one or two of those boxcars are slated to be moved and displayed elsewhere.
http://www.railroad.net/forums/viewtopic.php?t=33599
You could have then typed in search words relating to the Thruway or I-90 and found several threads about lines that are within sight of or cross over/under said highway.
http://www.railroad.net/forums/viewtopic.php?t=27171
Or maybe I'm the dumb one because in the end, in my attempt to prove my point, I did indeed do your homework for you!