The history of Stern is a little crazy. Sam Stern founded Stern Electronics with the assets from Chicago Coin and Seeburg. Seeburg had previously owned Williams, but spun it off into its own company when Seeburg went bust. Sam Stern had manged the Williams division, but didnt get the assets to it when Seeburg went under.

Stern Electronics went under in the 80s and folks ended up at Data East, then Sega. Eventually Sega got out of pinball and sold the assets to Gary Stern, Sam's son, to form Stern Pinball. This was about the same time Williams got out of pinball, and I think their assets ended up at a German company.