[Jim McDougall]

Philip, thank you again for this interesting view on this subject. It seems sometimes that we continue to learn more on these matters the more we review them.
In "The History of Chivalry" by Charles Mills (1826), the excellence of the sword makers of Toledo is discussed with Julian del Rey noted , and that his weapons had peculiar markings; el perrillo (a little dog); el morillo (a moors head) and la loba (a wolf).

In "Don Quixote" , Cervantes refers to swords made by Julian del Rey as being short and broad in the blade which were called 'little dog swords'.

J.J. Rodriguez Lorente in " The Perrillo Mark of the Spanish Swordsmith Julian del Rey" (Gladius III, 1964, pp.97-98), notes that the smith seems to have used the canine mark selectively on certain types of sword.
These seem of course to have been the 'jineta' type swords, but that on 16th century rapiers the marks seem to have been coupled with others, as if signifying various meanings.
The perrillo seems copied later in Germany, but here it becomes confusing, at which point did the perrillo end and the 'Passau' wolf begin?

Lorente notes in his article that the figure was probably intended to be a wolf but that it was likely mockingly referred to as a 'little doggy'.

The sword of Ferdinand III, (G21 Calvert) once regarded as the 'Colada of El Cid, is now believed to be the 'Lobera' sword of this King of Castile and Leon (known as St Ferdinand). Since this was 1201-1252, it does seem to pre date the known period of the 'wolf' used as a symbol or mark on blades.
This would also preclude my thoughts of a possible reference to the Passau wolf and blades from there, and seemingly before the wolf/little dog as well.

Still, the connections between the canine marks used in Spain, and those which evolved in Germany in Passau and later Solingen are compelling.