The dimensions of the penny were perfect though. It had the right diameter and wasn't so thick that you couldn't close the lid properly without touching it.
It was just too heavy so if you pressed too hard on one side it would just break off again.
So far the butchered Lego piece seems to be working out.
Don't really want to give it a real stress test though. I used some pretty tough super glue but I'm not keen on breaking it, regluing and waiting another couple of hours for it to fully dry again.