As I am in the University today, I just happened across this article while looking for something else. I am surprised this has been missed in the literature, the author found the name of the father of the famous Don Abraham Senior in the Spanish National Archives. Unlike the ridiculous genealogies that have proliferated, this article is sound, takes a critical look at the genealogies (in Spanish) and provides the sources. The name of Don Abraham Senior's father was apparently, a man by the name of Don Levi Senior (Seneor). Enjoy!