Clarification:
"Made in Mexico" was still Nintendo production, just moved to Mexico in 1996. For "Made in Mexico" versions, the cartridge will start with M/ and the Manuals will typically start with U/. Majesco purchased distribution rights in, I think, late 1997 and the wording "Assembled in Mexico" appeared to indicate that they didn't produce anything - just slapped some shells together with premade PCBs, some scanned label artwork/manuals, added in their logo and the "Assembled in Mexico" legal text, and sent them out.
Before the site went down, I know we had a discussion as to the origins of the box. I don't remember what it was off the top of my head now, unfortunately, or I'd add it to the entry.
![Cry](http://www.rfgeneration.com/forum/Smileys/RFG/cry.gif)
EDIT: Right... They had to redesign the box art to conform with ESRB ratings.