I don't know the model number but she really looks like my New Home AB. Was probably made in the late teens to early twenties. On the back should be a screw, maybe two holding a cover on. Remove it. The insides should look like the inside of my machine:
http://www.quiltingboard.com/vintage...l-t187261.html
Oil, oil, oil, oil, and grease the gears. Tri-Flow grease worked wonders to my machine.
Will probably take 20x1 needles that can still be had:
http://www.sewingshop.com/singerindu...dles-20x1.aspx
It might be you can short seat a 15x1 too. I can do that with mine, but it sews sooooo much better with a 20x1 in it.
I don't know what size bobbins yours takes, but mine takes a Boye #3, same as my New Home Greyhound.
Nice machine, love those flowers on the bed. Are they mother of pearl inlays?
Joe