The things that I found that indicate MIJ are as follows;
 Underside of bridge is marked Japan
All of the pots are marked Japan
The pickups read as follows  Patent Applied For
                                           Made By Goto
Unfortunately there is no serial number as I can see. 
It is just odd that there is very little info about Cortez guitars. I can say that the inlay work on the headstock is top notch, not cheap or poorly cut, but very nice. When the light hits it just right, the word Cortez and the split diamond inlays shimmer with purple, blue, pink and silver. 
 It could also be Korean, who knows?? I can attest to the Cort Factory producing good work. I also own a 1997 Fender/Squire Pro Tone Precision V bass that I believe was produced in Korea by the Cort factory. A VERY high quality instrument that plays nice, looks beautiful, and sounds great. I must admit, I do have a love for MIJ guitars, as I own a bunch. But, wherever this Cortez was made, it was done nicely, and for $80, I couldn't turn it down. 
 
 
Here are 2 more photos