Thanks for the fast pictures Fernando...
Regarding the kings head: maybe there is some kind of forgery into this.
As you said, Weyersberg / Solingen was a well known name too: So why not copy the marking and change it slightly to be sure to get no legal issues?
Is just a wild guess, but with your permission I will ask at Weyersberg directly (they are really nice people) if they ever used this kind of marking (or know of a forger who did.
Regarding the "S": As far as I know, you are right. It stands for Solingen. By the way: Blades intended to be sold to a foreign country are (as far as I know marked with an "A", perhaps for german: "Ausland" which means "Foreign Country"). In addition to this, it is interesting to know that Klingenthal used the same symbol with a "K" (logically for "Klingenthal") in it
@ Jim: Always a pleasure to help