I must say that during the 18th century every cavalry regiment in Europe with the notable exception of hussars and several Eastern European Cavalry forces used a straight saber which was left to become blunt to make up for the shock of an impact from such fearsome weapons; they were normally the length of a persons hand to the top of their head as shown in this picture.
Ignore the fact that the picture above is based on Napoleonic Wars, there was only some change in the design of a blade since the turn of the 18th century but none of it was significant
I noticed some cuirassiers using curved sabers; not to mention such weapons are unreliable when slashing at short distances and to control effectively. From my estimates at looking at the picture with the cavalrymen holding those sabers; I suggest reducing its height by lets say 20-25%. I know this mod is anachronistic and not meant to be exactly in place with history but those sabers are just to awkward.