From what can be seen in these pics it COULD be an original 3.R. period government dagger. Due to the crossguard and certain details of the scabbard let me assume it to be an EICKHORN more than an ALCOSO, can also be wrong on this due to the very bad pic.
Naturally better pics are necessary but the dagger seems to be worth to be examined.
You can send better pics at [email protected] (remove NOSPAM before sending).

wotan, gd.c-b#105

"Never look for sqare eggs" as a late owner of an original FHH-dagger used to say.