If you want to be exact about the subject, you will find an overview on this page of the historic eras and emblems for past and current European railroads. The division in eras follows NEM standards, but the newer eras are not precisely defined. Even in the prototype, there can be some overlap in the features of different eras.
The pictograms described for the eras can also be found by the models so that you can assemble prototypical trains from an era is question. The search function in our » Product Database also supports you here when you enter the era as a search criterion.