Hi there,
This is Bogdan from Romania.
I'm a mechanical engineer - specialized in the industrial robotic field, 3D designer and modeler (from time to time and some projects I could make the functional prototype too).
I'm doing product design, industrial design, reverse engineering, ideation, etc.
I have over 15 years experience working on various systems/devices across multiple industries, from concept to launch.
1 - i wouldn't recommend scaling up that model - while scaling up, besides the external dimensions, the wall thickness will also increase, so will be necessary to adjust after the model to fit your parts... (and other "nasty" behavior)
2 - as long as you could provide me the 3d model or at least the dimensions of what's necessary to fit inside the street light model, i could make a brand new model with all the elements (front case - with support for your parts, back case, pole - but i would advise you to use a regular pvc pipe, and the bottom plate) ready for 3d printing
3 - you will have in the end the 3d model of each part and the assembly as cad files (iges, step, stl, obj and 3d pdf)
Regards
Bogdan