bitbank:
That device is expensive enough with shipping that it's probably worth designing your own 3D printed case around your choice of display + microcontroller. Who knows what you'll find inside that device. It may be a black blob of epoxy on top of a microcontroller with no access to reflash the program.
It's less than 22 quid including delivery, from eBay sellers. That to me is a bargain. It's not far off what a basic needle gauge starts at.
3D printing isn't going to happen. The finish is fine for prototypes, but I might sell this finished item.