Twenty years ago since it was sold. It could have changed hands several times since then. That makes it a long shot on finding it. I looked for almost 20 years for my Grand Dad's 4010. I knew the serial number and the general area it was sold in. It still took time and luck to find it.
You need to get more information for people to be able to help you more. Better sales date and smaller location. Southern Iowa is a pretty big area to look in.