I have one of those out in my studio right now that is a customers machine. That is a badged National sewing machine. I cant see who it was badged for but the one I have is for Western Electric. It is a really neat machine and looks to be in wonderful condition. As for the year of the machine I can not say, I do not have enough information on those machines to date them. If you can get on the NeedleBar then you might can get the date from the serial number.
It is neat how the bobbin plate on the machine swings out and the bobbin case just pushes on the hook assembly.
Billy