Hi massimo
I'm not even close to a dagger guy by a long shot- but what you have is also a short as opposed to "long" dress/parade/"walking out" bayonet. They were plated, as ours both are- and really more for the pomp and circumstance than the battlefield ("combat" bayonets are quite different) I also have an eickhorn ks98 like yours, these were made pre-1945. Check out this forum's maker mark guide on the sidebar- and you can date your particular eickhorn that way. I think that's similar to the mark from 36-41, so yes- pre-45. However I'm hoping to see some more lutters marks (the lion) as I've not seen any on these bayonets... just a rookie guess, but I think carl eickhorn is probably one of if not the most common and prolific maker of edged weapons during the entire third Reich period. Still, condition counts- and imho yours looks pretty nice! Congrats!
Mike