Yes, I have seen this as well. There is something very strange about Lincoln where my jew-dar starts clicking whenever I get a good look at him. And his "non-specific" religion seems suspect at best. He certainly has all the signs of the marrano type.
Of course, his name is "Abe" as well.
It doesn't mean he was Jєωιѕн, but Abraham would have been an unusual first name for a Catholic child at that time. People were normally named either after New Testament figures or canonized saints from the history of the Church. Old Testament names were rare among Catholics. Nowadays, OT names are more common for Catholic children, but Abraham is not one of those names. Far better to have an OT name, than the pagan, epicene surname-sounding first names (all the Taylors, Tylers, Hunters, Madisons, Paytons, Haydens, Bradens, and so on), or the soap-opera names that are all the rage nowadays. The atheist Las Vegas magician Penn Jillette (a very funny man, by the way) named his daughter Moxie CrimeFighter.