the third quarter of sachsen-lauenburg coat of arms are no moons but three water-lily leaves, standing for the County of Brehna! see picture count Friedrich.
the crossed swords indicate the Saxon office as Imperial Arch-Marshal meaning the Saxon privilege to elect a prince.
This weapon of "kurzschwerter"are widely spread among the German nobility.
Unfortunately the logic of your theory in the previous post escapes me completely.
Due to the average execution and workmanship, this katzbalger is not very convincing. it looks like there is not much support to find, to designate this katzbalger as original 16thC.
though I also incline strongly to a later 19thC reproduction, it can still be authentic.
if you can live with this that's fine, if you want more certainty, you can ask a specialist/authority in the known auction houses.
For example, Hermann Historica; Robert Weis or Nicholas McCullough
they have made an excellent cataloque describtion of the Karsten Klingbeil collection.
best,