I posted a pic of a Singer 401A and a 403A on the picture page so you can see the difference. They are pretty much the same. When I found my 401G in the trash it didn't have a manual... LOL so it took some time to figure out the cam stack. Now that I found a manual I found out most of the manual info for stitch selection is right on the lid.
http://www.quiltingboard.com/t-130994-10.htm