There’s two ways you can choose to make a case mod. Either a) take something that really should never house a bunch of chips, circuit boards, and a GCU, hollow it out and ram all that stuff inside or you b) gut something else and supe it up in a feat of homage. The Sinclair ZX81 case mod by Unimod is in category b).
Slightly silly? Well, aren’t all mods? Manipulative and nostalgic? Possibly, but who cares. It’s good work and it looks ace. Good effort. Still love that keypad.