I inherited a Kenmore ultra-stitch 12 machine model 15814612. I need a bobbin case. I ordered one from the kenmore parts site but the one i was sent i think j155 is for newer models. I cant find the date the machine was made but guessing 60's or 70's, i included a picture of the manual. I live in massachusetts and am hoping someone knows where I can find this vintage part?? Thank you to anyone who can help!!