Cute indeed, 'Nando,
I must admit I have never seen anything of this kind, so all I can say is left to mere speculation. I think your idea of its showing Spanish Colonial influence may have hit the target. On the other hand we should not forget that the Inkas had developed a high culture before the Spaniards arrived. 17th century seems quite right to me but I cannot exclude the 16th c. either.
Anyway, take good care of this cute riddle, it sure will get to know some interesting comrades in your collection!
Best,
Michl