All of ours have been in Texas their entire lives, so no problems here. I can imagine that they would rust out over time with salt being put down on the roads during winter up north. The 74 FJ40 we have has very little rust. I searched and found this place:
http://www.tlc4x4.com/2000/home.htm
They seem proud of the items they have though. I think the only thing we have replaced due to rust is the exhaust from the cat back, and hangers. It was only $120 at the dealer for the complete set up.
Let me know what else I can help out on. What service might you be looking for out of one of these vehicles?