It may happen that main version will not be assembled due to small clearances. Actual clearance depends on many factors (flow, filament, printer condition)
Parts with the letter C in their name are parts that have increased clearance. These parts must be glued.
the box part is solid. the locking part doesn't seem to be equal on all 4 sides. might be on purpose. i glued the part that goes on the hinges. i also snapped off the wheel test fitting it, just glued it back on. i would love for the wheel to have to turn more to lock but it works. i am sure my niece is not going to care about any of these things. thanks for making the model.