Maybe the more experienced Collectors can chime in here, but Horn and silver is a common motif for Luzon-region philippine daggers. Also, the hilt seems less bulbous than most Alcabete I've seen (admittedly, google is my only experience, hahaha) and more in style with a lot of Spanish-colonial influenced Philipine daggers.
What DOES look different to me from most Luzon pieces is the sheath. Most Luzon pieces are leather instead of hardwood. An exception to this is southern Luzon. For example, the Minasbad, a blade native to the Bicol area, traditionally has a wooden sheath.
Maybe this dagger is Bicolano in origin?
