The Junkers J 9 was the world's first all metal fighter. The type first flew late in 1917 and only one original survives in the Musee de l'Air at Le Bourget. Manfred Pflumm, the Director of this museum, was well known for building replica aircraft which are featured in museums across Germany. This example was either nearing completion or dismantled and it may be the example that I saw at Gatow in 2006. That was removed from display in 2016 when it was acquired by the Luftfahrttechnisches Museum in Rechlin and where it went on display in 2017.