With BTTB the development of TT-models came almost to a hold. Quality became less important, especially during 1975 and 1985. The old Zeuke models from around 1972 were more durable and had a better quality. Nevertheless there were a few improvements like the more detailed printing on the models. Around 1990 the plastic wheels were at last replaced by metal wheels. This brought also a change in the article number, it went from 4 digits to 5 digits with a leading “0” or “1”. A model with a leading “1” had metal wheels. See the cattle wagon 14820.

Around 1991/92 there was a disputable improvement: the package became much better and even luxurious. The used white box made the product than much more noticeable. Collectors argued that they rather wanted more models than this expensive package. I would say, if you want to sell a luxury product you can not use cheap cardboard to wrap it in.

New models during 1972 – 1993:

Locomotives:

• Steam locomotives; BR 56, BR 86 and BR 01
• Diesel locomotives; V100 / BR 110, BR130 / T 679, BR 119 / 229
• Electric locomotives; BR 250 and E 44

Coach and Freight wagons:

From around 1985, models were made distinct by the period they were used. There were five periods defined, Period I, before 1920, Period II, 1920 – 45, Period III, 1946 – 1970, Period IV, 1971 – 85 and Period V, from 1986. The wagons had different markings and signs according to that period. Another distinction was made by the railroad companies. In the eighties models from more and more railroad companies were available, such as:

• KPEV, State railroad of Prusia
• DRG, German National Railroad company
• DR, National Railroad of East Germany
• DB, National Railroad of West Germany
• DB AG, Railroad company of re-united Germany
• ÖBB, Railroad company of Austria
• SBB, State Railroad of Switzerland
• NS, Dutch Railroad company
• SNCF, French Railroad company
• SJ, State Railroad of Sweden
• CSD, Czech Railroad company

The use of different railroad company logos on a model in combination with markings used in different periods provide a high number of versions per model.