I had a USB Battery pack who’s case got smashed. so I designed and 3d printed a new case, and while I was at it, added a newer circuit board to it that has USB-C charging capability.
PCB: https://www.aliexpress.com/item/1005001965710528.html
The lid of the case is super-glued down. I was going to make it a screw closed lid but the design effort and sourcing of suitable screws was just too hard. If I ever need to open the case I’ll just 3D print a new case (probably with some enhancements).