Your project looks good Patrick. It's a good idea to 3d print the case. I did try to print a case based on
https://www.thingiverse.com/thing:732237 on my XYZPrinting Junior but the lid and the box did not match properly plus the finish was too rough.
And thanks DFN, yes, I've a large selection of spare cases now from the PiHut, RS Components and Farnell! The kids are busy filling them with weather stations, badger cams (which has only taken one photo of a cat) and smart light controller. :-)
One day I'll find the smallest possible box that will fit all the components plus has a access door for the sim card.