AH I bought out an old home ec class room full of Singer 404 machines one time - none of them ran - I sure did learn a lot - I have 4 more motors to re-do. It's isn't hard once you have done one and they sure do run better after that. I had to re-do a bunch of tensions - most of the machines were totally frozen up inside. I got all but 2 working - had to have parts from some place. One is missing the needle bar, a tension, a motor, a stitch regulator and a motor. I gave the other to my grandson to play with while mommy sews.
Billy, if you are buying out sewing machine shops you need to check out Arbuckle's Railroad Place up in Noblesville, IN