Assets held in a 401(k) plan are completely protected from creditors. IRAs have some protection, but not complete protection like a 401(k) plan. The difference is that 401(k) have a spend thrift provision which specifically provides protection from creditors. IRA protections vary from state to state and have a dollar limitation. Like OJ, if I wanted to protect my assets, I would roll my IRAs into the 401(k) plan.
You could attempt to set up a trust, but it is difficult to set up a completely protected trust if you are funding it yourself (self settled spendthrift trust). Seek legal advice, you can afford it.
Every legal matter is fact specific, and there are often nuances in every case. This is intended for comment only, and does not create an attorney client relationship.
If it's been twelve years then there may not be any liability because the limitations period has passed. Spend the money to hire an attorney to look at the possible claims and how they may attach to that property.