Lets check other calculators with the same face - just in case somebody will need to independently reproduce this project - CASIO fx-82ms, CASIO fx-300ms and "NONAME" from Amazon for $7.99:

Without packaging they look exactly the same (except for solar cell on fx-300ms):

1st one is fx-82ms that looks DIFFERENT from inside:

2nd one is fx-300ms that looks similar to fx-82ms, but with 1 button battery instead of 1 AA and solar cell:

3rd one is "NONAME" that is DIFFERENT from originals and from previously opened clone:

Interesting observation: clones use 2 batteries while originals use only 1 (AA or button).

So no reproducibility yet...