The smelter is a balsa structure clad in corrugated styrene in individual panels. window frames are made from balsa strip, as is the canopy over the actual smelter.
The smelter is a piece of metal tube with styrene accessories added. The whole structure is glued to an 1/8 ply base to allow it to be fixed to the layout at a later date.
The model is painted and weathered with model enamels.