When you go for the viewing day make sure you talk to the guys in the yard. They are usually quite helpful and will tell you what is wrong with the vehicles, if they know. Ask them to start some up, they should be able to start the ones which run. When we bought ours we heard it running before we bought it, and that was from a tender sale. I don't know what condition the vehicles in the tender are in, but there are usually some good runners.
How far do you need to move it? I don't think your tractor will be able to pull it. I pulled a dead tractor like that, which was totally siezed up, using a 432 and it didn't even notice the tractor was there.
Chris