“If a spouse (husband) conceals substantial financial gain acquired during a 26-year marriage, and withholds disclosure of this overseas bank account in a divorce settlement, and then the other spouse (wife) finds out about the concealed money–after the divorce is finalized; can the wife reopen or sue the husband. And is there a time limit in the state of Mississippi.”
In California there is no time limit to pursue an action based on a willful (fraudulent) non-disclosure of marital assets. The penalty is 100% of the interest by statute. Check with a Mississippi attorney, as there is likely similar relief available there.