I've got an old Kenmore, model 158.17300, which I believe is about 40 years old. My mom used it for clothing construction, and then I took it over after I graduated high school and have been using it for clothes and then quilting ever since. I get it cleaned and lubed every couple of years and it works like a dream! I might have fun with a fancy machine like a Bernina or Pfaff, but I don't even try them, because what I have does what I need just fine! (I piece, and only machine quilt small projects.)
As for the bobbin...check the tension on the bobbin case. Maybe a turn of the screw would prevent that sticking.