Built by "a precision mechanic with a small company in northern Germany that mainly equipped marine school" (Eigenbau means "self-made" in German) (6 or 7 copies?) - Andreas Scholl (Austria)

- 1958: Arge Maritime Landschaft Unterelbe, Grunendeich, Niedersachsen, Germany

- 1960: Koninklijk Instituut voor de Marine, Den Helder, Netherlands