Agaricus bisporus has covered most of the German prone pilot powered aircraft (the Horten Brothers also worked on prone pilot gliders). However, there was also the Messerchmitt ME P 1103.
once again I'm amazed at what I find digging into the background behind this thread.
One of the most interesting things about the three challenge threads (cockpit, silhouette ans airfield) is getting the brain cells working an learning something new.