This handle is installed on the inside end of the flat lever arm window operators in late 1970s Airstreams. Ours is made of zinc with chrome plating. It is a replacement for the obsolete plastic version which was ivory color. It was Airstream part number 380227 or 683976.
We know the flat lever arm style was used on many (but not all) Airstream models from 1975 to 1979. Let us know if your trailer falls in a year outside that range.