This machine was a gift from one of my sisters (I think they call it "enabling"). I've seen pictures of them, seen them for sale a lot, but never up close. It wasn't in too bad of shape, except the motor, and cleaned up nicely and sews well. The motor was another story, didn't move at all, but it worked out.
Turns out the motor on this is reversible. I'd wondered about non-sewing machine specific motors before
Running a sewing machine motor on direct current?
And I guess this is another example. The brushes are in opposite ends of the copper tubes marked with the arrow. That tube is one piece and the brushes are opposite each other, and it rotates in the slot. When the marked tube is in the down position it moves the machine correctly, when up it moves the machine incorrectly (I think...). I have no idea how it works electrically speaking. I wonder if the original manual addresses this. I had seen one other picture of a machine with this swing away motor, a Singer 15, but had no idea what it was.