I dunno, I would say the negative stigma associated with that period is still too prominent to make it a distant historical curio. That was a very militaristic period for Germany (if they ever had a non-militaristic era) that saw the initiation of the First World War and was the precursor to Hitler's, who was a soldier then, Third Reich. There are a few WW1 veterans around and plenty of older people who were strongly affected by the period as children or infants. Many white supremacists in the U.S. fly flags from the Deutsches Reich (black cross on white field) and wear their helmets and uniforms. Sure nobody is going to notice your buttons, but I personally wouldn't want that on my suit just from my own perspective.
I did some research, and they are from the period of the Deutsches Reich (1871 till 1918).
I find these antique pieces more interesting that contemporary buttons. There is so much more history and culture behind them than a modern replica from H&S. Also, these buttons in particular are by far more characterful than H&S's selection, and far cheaper (less than 5 Euros for all six). I also imagine them to be more quaintly made (they have words like "extra fein" and "feuervergoldet" stamped behind) I think there is no harm in giving these historied pieces a new active life. They would give my navy blazer congruousness to its category of garment.
Can you find buttons from other slightly more banal navies from that period? (NZ navy? )