During work on the windscreen i realised that in folded position it overlaps the fuel inlet.
The original inlet was sanded smooth, and new one was built on the side of the body.
Similar pipe was installed on one of the first prototypes of the Kubelwagen.
I use the Tamiya cup, and some scratched details to complete the set up.
With such wide fenders, as on the Kettenwagen it would help in refueling the vehicle i imagine.