Running into this thread is why I got a login. I had one that looked like this, and I was to understand the model number was 602, but. The lever should be to the right, so the feed dogs engage. Lever to the left, will allow you to pop the throat plate off. Messups in the bottom where the bobbin drops into, the shuttle part that brings the thread around, was a common issue and that would cause issues with my feed dogs.
The bobbins were called 'touch N sew', came in 2 packs. I still see them for sale. The two sides are uneven, one side is wider, and unscrew as well, to two halves.
I hope you got it running. I loved the infinite stitch length dial, the NO HOLD reverse (slide lever all the way up and you could lock it there) and wind the bobbin in place.