I have the same suspicion. The whole coin looks good, but some details are weird. The obverse is Spanish after 1597 because the presence of a little shield of Portugal, but the value (IIII) is horizontal like in the coins before 1597. The only use of the shield of Portugal in Spanish America, that I know, was in the mint start-up of Santa Fe (Bogotá, Colombia) in 1621 with dies imported from Spain. See the 2 reales N#61427
The reverse has the combination octolobe with circle of beads used in Spain before 1597 and in Perú (Potosí and Lima) throughout the XVII century. The crude manufacture is typical of Potosí.
Jonathan, perhaps you can draw attention on this thread of the referees of Perú, adanieluy and jasanche. It is an interesting coin or …