"Papaw" here is more likely an alternate spelling for Pawpaw/Pawpow, which is actually Popo. During the centuries of the Atlantic slave trade, European slavers referred to a region along the West African coast in modern-day Benin/Togo, and to its people/language, as Popo. Today there's still a city in Benin called Grand-Popo.

The Portuguese, Spanish, and Dutch certainly operated overseas slave trade rings in the Indian/Pacific Ocean. The Dutch East India Company (VOC) was even involved in purchasing slaves directly on New Guinea, although my understanding is that the Dutch Pacific trade mostly remained in the Eastern Hemisphere. (The Spanish Pacific slave trade kidnapped a lot of people to Latin America, especially Mexico). Still, I think the reference to "Popo country" is more likely than one to Papua, which was probably more likely to be referred to as New Guinea at the time in any case.