The writings look correct. The good writing characters are incredibly fine in execution. They can be tiny letters. Here you will see big differences in the "modern."
Batak is a highly copied culture. Most of it Islam and Christian and the old shaman ways fallen into disuse. This could be real, but I regard most items like this as curiosities unless a knowledgeable person has been able to hold it and offer an informed opinion.
Authentic Batak pieces are very rare and extremely expensive. Depending on price, I'd buy it for the artistic work. Looks nicely done. However I would ask for high rez pictures of the writing.
Interestingly enough a Google search of "Batak Religion" asks if I want to change "Batak" to our new president's last name. Guess it shows he is more popular than a North Sumatran culture.
