They are actually cast items, made of a plaster-like compound with a top-coat to give gloss and hardness.
Usually they bear the initials "WE" or a foil label with words such as "Wolf Originals" "Fait a la Main" "Made by Hand." Similar items are made under the names Greg Wolf, or Wolf Enterprises, as well as other names.
They are not carvings, and are not made of soapstone. Original prices were $5 and up.
One may find more info online by googling Wolf Originals.