The Ausbausystem 1 S was the Schülerübungssysteme version of the Ausbausystem 1 (8100) model and added the an A4 format version of the 1101 model’s Elektrik II Lehr-und Lernkartei (teaching and learning cards) documentation. The A 4 format Elektrik II documentation was published in German, French, Italian, and English. The Elektrik II documentation in an A 5 format was not published.
I can confirm this because I was able to acquire a previously never opened Ausbausystem 1 S model which included a 1971 catalog and its layout matched the above layout photo exactly. Unfortunately, Braun does not appeared to have put a photo of the Grundsystem S or Ausbausystem 1 S models in any published document.
The opened box layout.
During the LectronMW era, a different plastic tray was used and the layout reflected the transition of the three mentioned blocks accordingly. One banana jack block was also eliminated.