Thank you Delyse for the abstract of the will. I guess the follow up question is, Did Richard Saint George (who married Elizabeth, daughter of Nicholas and Elizabeth) assume the surname of Saint John? Before we weigh the probability, we have to keep in mind that that's precisely what the DePorts did, they married into the Saint John family and assumed the surname.
I think that anyone with high profile ancestry are going to discover several "non paternal events" in their lineage. DNA testing is assisting us in that discovery. Proving who Richard actually was is part of this process.
I have just discovered that my great grandmother, who married Elmer St. John (my great grandfather) is actually related to Sir Oliver Saint John. What a strange journey this has turned out to be for myself!