While it is true that some counterfeiters repackage some used gaming products in new shells and new packaging I don't know if that has been done with any Wii Remote models. Even if that has been done with Wii Remote Plus controllers it would mean that removing the shell and having a known-genuine remote of the same revision (internally) for comparison would be necessary (unless the guts are really, painfully obviously fake).Just because the box might be unofficial doesn't mean the controller is. The build quality looks and feels identical to the Mario remote as well as the response on my Wii.
The only comments I have on the Mario remote are that:
1) It looks like other units of the same model have three gold contacts in holes in the battery compartment. Both of your controllers have the three holes, but there are either no contacts (just holes) or they're not gold. I don't know if any genuine controllers were made without the gold contacts.
2) The upper-right corner of the top part of the shell (red plastic) doesn't appear to be flush with the bottom part (blue plastic) based on the shadow the top part is casting over the bottom part in one of your pictures.
I don't plan to look into this any further, at least not right now. A picture of the holes with gold contacts in the battery compartment has been attached for reference.