The serial number is on that little plate on the right front of the bed. That's all you need to find the year and model here.
http://www.singerco.com/support/serial_numbers.html Let us know what you find out. I have an idea and would like to know if I'm right. Or post the number.
I downloaded my repro manuals free from sewclassic.com
It's a very pretty machine and your bentwood case looks good, too.