I'm pretty sure that is a 404. I have one just like it. The 301 has the bobbin on the side, under the flip up part, and yours has the drop in bobbin.
You can use the serial # to find out what it is on this site:
http://www.singerco.com/support/serial_numbers.html
There are a couple of Yahoo groups that may interest you....Vintage Singers and Singer Slant Sewing.
If you join either of these groups you will find lots of information in their 'file' section. I have also found PDF's of the manuals for my machines.
ETA: Here is the manual for the 404. Congratulations on your 2 babies!! :mrgreen:
http://www.ismacs.net/singer_sewing_...ng-machine.pdf