Money Box with replaceable top

Money box to be mounted on glass jar.

Parts "Bottom" and "Under" should be mounted on jar lid - it is necessary to cut inner hole and drill side holes for M3 screws in the lid. They are mounted with M3 screws.
Then part "Upper" is mounted via hinge to part "Under" with using long M3 screw. On the opposite side there are eylets for little lock.

Part "Top" is replaceable (one M3 screw) - so one could change it when needed. My plan is to make Top for each month, so new designs will be com