Before the internet, a company sent out large catalogs to casting agents/producers, etc. that listed actors/actresses of all ages for hire. Agents paid money to list their clients in these catalogs. Here are three of De’s listings. In the first one (pre-Star Trek), he was listed in the “bad guy” section. In the other two, he was listed under the “leading man” category. I love his forehead curl in the second listing.