I was just trying to help clean up an instance of UNKNOWN, and this one seems obvious at first glance, but i've never done anything in Finland. I'm not entirely sure that his mother really had two husbands - there might be two different Maria Christina Heermans for all I know.
Anyway, if his last name is Petersson, why is he connected to the other husband for his father? And are those duplicate sisters really duplicates? or a case of the next child being given the same name as one who passed away? Maria Christina with two different dates, and Britha Catherina and Birgitta Catherina. Can someone knowledgeable about Finnish sources please take a look?