This is an exact replica of the original toolbox of the vespa piaggio ciao.
Mounted under the rear part of the bike just above the wheel.
This toolbox design fits on all models, even the 1970's versions.
Allows you to take a small sparkplug wrench and a spark plug with you. Perhaps a screwdriver and an adjustable wrench.

I suggest using petg considering it's uv-resistance and slightly more flexible properties.
But I have tested these in PLA and that also works just fine.
Print without infill.

If you decide to make this part, please let me know and upload a picture.