Client's husband died almost 20 years ago. In 2020 she received a check from the state for unclaimed funds. There is no paperwork available and the only notation is for dividends and stock sale. He was a pilot for one of the major airlines so I am thinking it must have been company shares but the wife has no idea when or how purchased or how many shares. Any guidance as to how to come up with basis? The amount is about $20000.