Not to bring up an old thread, but I've seen this engine up close.
http://www.dragonmnt.com/prr.html
There is a LOT of rust on this creature. And she is missing the rod from the piston to the main rod.
http://www.dragonmnt.com/PRR2-10/IMG_0043.jpg
Example of the rust, this pump looks to be holed from it:
http://www.dragonmnt.com/PRR2-10/IMG_0045.jpg
I'm gonna get back up there with my newer digital camera sometime, but for now I'll just apologize that the pics aren't as good as I would have liked.
While I'd love to see this thing run again, I'm not sure it is financially feasable in today's market. I doubt there would be much public support for such a project, and railfans and museums can only offer so much money before running out.
Man, this reality thing is a bummer!
Michael