Can't help with the question on liens, but I'll add to your torment with something I learned from my local Case Dealer. My dozer had an issue with one of it's hydraulic pumps that only appeared after it was warmed up. They do not fix these things, they only replace them on my particular dozer. It might be different on other models, but I honestly don't know. The replacement part was $25,000 plus labor. I have three pumps, so there is the potential that eventually, I'll need all three replaced.
The dealer told me to take it to the auction and let somebody else deal with it. That's what they do, and what they recommend to their clients when they have a repair that is more expensive then it's worth.
A contractor that I know bought a low hour John Deere 710 loader backhoe at auction with low hours for a fair price. Once he started using it, he felt it was under powered and burning a lot of fuel and oil. His mechanic found that the injector was plugged with a BB so you wouldn't notice the problem at idle, and when not under any load. He had to have the entire engine rebuilt.
Auctions are where people sell stuff that you cannot go back to and complain about.