Of course it *could* have been given to someone from the factory, but somehow I doubt it. (such a present doesn't feel very ... Swedish)
As I understand, Strömbergshyttan (the village) was a close knit community, and still is (even though most have moved away) - so my guess would be an "internal joke" sort of thing... Guess is a key word here.
However, the -s ending implies, as you say, "of Strömbergshyttan". Nice piece, and a nice mystery!
Kerstin (who has only lived in the area for 25 yrs, so I'm still "new")