You have a badged National! When I say badged I mean that National made the machine for someone other than them. It was a common practice for National, Free, Davis, and others to make sewing machines for department stores and other makers.
It looks to be in wonderful condition and will more than likely clean up really nice. I have tutorials on here that will let you know the process of refurbishing the machine without hurting the integrity of it. Go here and you can find all sorts of information about you machine and others like it!!
http://www.quiltingboard.com/virtual...jsp?vsnum=1013
Billy