Hello Wim, for me an old, well known fake (I think it could be one of the prominet Atwood fakes). Custom daggers (water and land-) did have the distinct arcanthus leaves embellishment not this oak leaves one. There are even more differences (eg. grip) but this is the most obvious.
Rergards,

wotan, gd.c-b#105

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