Looking at photos of the belt gizmo in the video game it’s clear it’s not based on the ICC-808D, Does anyone have any idea what circuit board it IS based on? I’m assuming some other calculator but I’d love to know which one!
Problem is, it could literally be anything, depending on what reference was used by the texture artists. It’s even possible they made something from scratch.
Without knowing what reference was used, it’s next to impossible to know what it came from. 
Honestly you can get away with just using a GB1 styled gizmo and I really don’t think anyone will know the difference or call you out on it…