Coming to the smaller parts; roof hinges, hand rails and steps.
The roof is hinged. I could not find hinges, due to Corona regulations, which keep all the DIY stores closed here at the moment. So I took a look at some YouTube movies about designing these hinges, and made a drawing in Solidworks. The aim of this hinge is to keep the point of rotation outside the roof line. This way the roof can be opened without colliding with the side wall.
Cutting 3 mm grooves for the base blocks of the roof hinges
The aluminium blocks
Steel strips for completing the hinge.
A drill end stop, so I can pre-drill the wood for the screws, without drilling right through the side wall.
A back plate to give support and getting the hinge in the correct position.
The roof in the open position.
A box on wheels.
Corner profiles
The hand rail, made of 3 mm welding rod.
Bending and flattening end of the side grips.
The supports for the steps.
The support for the step under the main doors is a bit hefty, so it will not bend if knocked.
The frame partly disassembled, for drilling and tapping all the holes for the steps.
Wooden steps, with an extra steel support plate.
Englische Garten Bierwagon (nowadays Stuttgarter Hofbrau)