Stan's buddy Frank Marshall Davis could have fixed him up with the mother.
Of course, along with solving any genetics problem, that would also answer the eligibility question once and for all.
Given the known fact that Stanley Ann Dunham’s divorce papers report the natural father and the legal father of the child was Barack Hussein Obama, a citizen of the United Kingdom of Great Britain, the child was born with the same British citizenship of the recorded natural and/or legal father even in the circumstance where and if the genuine natural parents had been Frank Marshall Davis, a U.S. citizen, and Madelyn Dunham, a U.S. citizen. There is just no getting around the fact that the late Barack Hussein Obama was the person conferring British citizenship on the child by virtue of his status as the natural and/or legal father no matter what other natural parents can be dreamed up.