Finescale Railroader magazine has a website at
http://www.finescalerr.com/ This is the only magazine I know of that publishes the whole thing on line. Search their site to see if they have any building plans. Most of their articles are for large scale, but you can change the scales.
The NMRA's website has one of the best web directories going:
http://www.cwrr.com/nmra/ You dont have to be a member to use it. The Mid-Continent (I think ) Region has a newsletter called the Hotbox that has plans for buildings of a Michigan nature. Do a web search for "The Hotbox Model Trains"
Federal copyright law says the original magazine purchaser has the right to make copies for their OWN use, but does not have the right to distribute copies to others. So who's to know?
We cant build models of CSX equipment and copyright them...they already are copyrighted by CSX. If anything, CSX can stop us from building the models. I've heard , for years, how railroads require a license to manufacture models of their stuff...(part of the idea of a copyright is to tell the users that its yours, and you retain the right to decide who uses it and what for). I have never heard of a railroad charging a fee to model manufacturers to model their stuff, nor have I heard of a railroad prohibiting modelers from modeling their stuff. Its a matter of controlling who uses it, and what for, so your copyrighted material doesn't get connected with shoddy materials or some rip-off scam. Seeya, Bill