I love the New Hobbyist's scale model proton pack, and I wanted a Christmas ornament version of it, so I just added a hook at the top to be able to hang it on a tree. 

I also did model the knob for the crank generator as the original didn't have it. 

Included ornament is only the pack. For the rest of the parts, please go to The New Hobbyist's file and download them there.

https://www.printables.com/model/72043-scale-model-ghostbusters-proton-pack