Wow! In your spare time, you can show the markings of those 20 frames... it's a big challenge
TTB = TSX century geo...
century geo is "more comfortable" for longer distances than the "aggressive" earlier road racing geo.
The EM Century model is not the same as the century geo - the model was built between 1988-1994 (Reynolds 653 tubes, then Columbus TSX), geo was used in models: Century, Corsa Extra Max, Mx Leader, Corsa 01, Strada OS, Arcobaleno, Corsa Extra SLX, titanium and aluminum frames (from ~1995 it was the only geo in EMC).
In Century model both versions of fork crown were used (earlier and more often: flat).
Translated with
www.DeepL.com/Translator (free version)