Thank you for continuing to update this thread Ludwig!
Seeing all the beautiful bikes built all over the world for the last century reminds me of the refrain from one of my favorite songs from Nas:
"Ain't no idea original, there's nothing new under the sun, it's not what you do, it's how it's done..."
By bringing the past explorations into motorbicycles into the forefront you are helping us all to make better bikes and renew old styles which worked out so beautifully.