Real Estate Law USA.com

My husband is filing a claim against the estate of his ex mother in law. The item he are seeking was promised to my husband by his ex mother in law, but his ex wife refuses to give it to him. She has also stated that she will destroy the item before he’ll ever get it. Her siblings are aware and willing to testify that the item was promised to him. An auction of the real estate and personal property is scheduled for November 15th. What can we do to prevent this item from being auctioned off until the ownership of it has been decided?
The item was not listed in the will. It was a gift from my husband to her back in 1983. His ex in laws have said they will testify that they have always been aware that the item was his upon her death. His ex wife is just being nasty because she is miserable.