Very nice example you show there Chregu!
It seems agreed that the Spanish influence here is pronounced, and as I earlier noted, the openwork piercing in the center of the blade is a characteristic feature of the renowned work of edged weapons of Albacete in Southeast Spain.
I thought it would be interesting to look a little into what these cutout designs might represent. R.D.C. Evans describes the plug bayonets made there, many of which have this feature which he describes as a dumb bell shape. The punched or pierced holes in configuration are also a decorative feature seen on many of these weapons.
The edged weapon makers of Albacete have a very long standing tradition of many types of fine edged weapons, and of course many were intended for hunting, including the plug bayonet, which were used by Spain probably longer than anywhere else.
The bladed polearms used in hunting, especially boar hunting weapons, often utilized a crossbar or toggle past the end of the blade to prevent the animal from making its way up the shaft to the hunter. Many of these weapons had a pierced aperture to insert and remove the toggle, though it is unclear why one would want it to be removable, unless perhaps if the weapon would double in warfare.
Evans recounts some of the rather romanticized notions about the openings being to hold smeared poison, a rather nonsensical theory often proposed concerning many medieval daggers with pierced opening or slots. Since many of these apertures are fitted with brass inserts, there is even a suggestion of these openings being for hunters whistles?
In my opinion, these were simply a decorative feature that might be a vestigial reference to the pierced openings for hunting toggles on the polearms that may have been produced in Albacete along with other edged weapons. Perhaps the shape was to allow insertion of a crossbar with this type cross section. Just a theory, and would of course like to hear other opinions. It does seem that a center steeped in the tradition of Albacete, that such a trademark feature might well be emplaced.
Whatever the case, it seems more established that these extremely attractive knives were probably produced in Spanish Morocco, carrying the traditions of Albacete in thier motif.
All best regards,
Jim
****finis******