I suspect that when hmaag posted the pictures, one of the pictures covered up the first digit of the serial number. My guess is the SN is probably 15773; maybe 25773. I hope hmaag will respond. With the 2-line patent dates where the top line is weak, that means it is quite early. I don't know the exact SN range where that die started showing a weak first line, but I think it is document in one of Kopec's books.
ERROR: See Following Post!
ERROR: See Following Post!