#10 - Mathias St. John [Sention, Sension, Santkin?]: Mathias was the focus of a Salt Lake Institute. A well-researched article was published in the NEHGS Register [Apr 2013] stating that Mathias was the son of an Antwerp-born button maker and an English woman named Joan. I was able to cross-check many of the resources. I had also corresponded with a researcher who credited St. John with a royal Welsh heritage.
Although I am still leaning toward the Dutch/Belgian lineage, I am not 100%sure.