To achieve the most ergonomic arrangement of the knobs and pots, I drew them, cut out the printout with scissors and put it on the appropriate place.

With the real hardware and some imagination I checked the right position.

Placement of Kompmonenten

Battery compartment and preamp

On the inside of the electrical compartment it looks like this. Also the battery compartment has to be right (also think of the cable holes!). The preamplifier from Mike Christian is fixed with sturdy adhesive tape.

Location of output jack