I have a question: I have a 301A with a serial # of NA 223654. Now I've been to the Singer dating site and I can find out that she was made in Anderson, SC, and between the years of 1951 and 1959 but cannot even begin to figure out how to get to the allotment date. This is because all I've seen so far stops with the A and another letter or the E and another letter serial number. What am I doing wrong and where do I go for more info? Thanks in advance, Chris