Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

The workshop tools are certainly molded, as seen in the photo above, but the steam engine frames sure look to be sand castings to me.

From my very limited knowledge on the subject, does that generally mean the moulds are wood (or metal?) and the two halves of the mould are made out of green sand, pressed together and then the cast iron is poured in. So it needs a new green sand mould made for each casting?