The good: A repaired 15-91 went to my sister as she wanted a machine 'like Mom had'.
The bad: I had to snitch the long spring from a bobbin winder from one 15-91 machine to another yesterday. I feel bad taking parts from one as I'd rather fix them all. :9
More good: I did a test sew using a blue jean cut off hem, folded it in half and sewed through all 16 thicknesses including the hems. It sewed just like a butter knife going through soft butter.