Its a very nice sword, Congratulations ! I agree that this sword is for use by the horse mounted carry or in German language "Reiterschwert", as some choose to use. In English, Reiterschwert = Riders sword.
The dating to the late 1400'hundreds also looks about right. We can say for sure that it is not an Estoc. The blade is not made for piercing plate armor or good quality mail of the period.
Definition of the Estoc:
The grip and handle on the sword could easily have been fitted with an Estoc blade but it is not. The length of the blade is also about the same as on an Estoc as the Estoc's is also made for the horse mounted man.