I had 2 ancient Singers I wanted to sell, but needed to know their age. I emailed Singer (www.singerco.com) with the serial numbers and models. They were very helpful and able to tell me the years and place of manufacture even (which was 1936 and 1941, Clydesbank, Scotland).
Incidentally one went to a retired chap from UK who used to sew in his teens and was taking it up again. Other to a french lady who was going to use for patchwork.