Cheers for that!
The two large hoses are for oxygen in the cockpit according to my ersatzteilliste... There are oxygen tanks in the tail, but maybe they were only used at heights where outside oxygen became too thin?
Now.. the smaller thin pipes you see running below the thick hoses, those contain the window cleaning solution.
The forward tank is actually the 55 litre oil tank.
Look at the pic below from ZM. It's cute they give you detail, but it's just a crude representation. What's the use?