Hello Michael,
I know why I have been careful with my guess about the age before but that the dagger come without a sheath have let me think that it perhaps an old one. But a sheath can be lost as well by a copy. Since I know that you own several of this kind of daggers and you will have some old references as well I am sure that you are correct. But on the other hand I have to say that the Dagger from Daniel shows a good patination at the brass handle what show me again to be very careful by casted brass since it seems easy to let look it old.
Best regards,
Detlef