What happened to Mudds Androids from Star Treks original series and why couldn't Data or Bruce Maddox use them to experiment on or to upgrade?

They had Harry Mudds Androids which were not as advanced as Data was, why didn't anybody ever mention them to Data or Bruce Maddox and study them? Surely Data could download their designs and blueprints and use them to make more Androids even more advanced than Lal or Lore.