Please examine the photo I provided of the Ausbausystem 5. You will see a Diac (8100 425), a Thyristor (8100 423), Zener Diode (8100 422), and a ‘Leistungsdiode’ (8100 421) in addition to the Triac (8100 424) that you mentioned.
This is a very rare model despite its longevity in the price lists. I can’t tell you too much about it because no instruction manual came with this particular unit. I therefore cannot say what are authoritatively the correct blocks that should be in the ‘official’ Ausbausystem 5 model. There is no known cut sheet or brochure for this model either.