Hi everyone, thanks for the replies. The suggestion about the AGs office and/or the police are helpful. I'm also going to talk to a lawyer friend of mine and see what he thinks my options are.

The piece is here in the warehouse locally - my wife has laid eyes on it. The local mover just refuses to release it to us until he gets even more money than he has already been paid (the original contracted amount). I am trying to get a copy of the original shipping contract my inlaws agreed to to figure out what the terms are exactly. It seems like every time we talk to the local mover he adds one more fee for us to get our property back.