Geno, I don't accept the title of "expert". However, when the American importer of West German Sauers called the guns "Model 60's" and "Royals", that's what Americans are going to understand. What they might have been called somewhere else is mostly relevant if the owner happened to buy it somewhere else. And chances are, he probably bought it in the United States.
Jorge, I too like swivels. Cheekpieces I can take or leave. I've seen Royals with both splinters and BT's. The 61 Stoeger book shows a splinter and does not mention a BT, and it says double triggers only. ST and BT must've come along later, because I've certainly seen Royals with both.