Transportable buildings of metal; pontoons and landing docks floating and stationary; common metals and their alloys for further manufacture including unwrought and semi-finished common metals; metal tubes and pipes; doors and windows, including skylights, roof lights, cellar windows, vertically pivoted windows, mesh windows, horizontally pivoted windows, and vertical skylights; valley tubes; ready-to-fit building components, namely, ready-to-fit building components for roof construction and ...