Does that badge on the pillar, just below the stitch length lever, have a blue outter band around the gold? Does it say Centennial anywhere on it? Nice looking machine. My first thought after turning the photo right side up was 15-91, but someone else has already vetoed that. As for a bobbin case, are you sure it needs one, or does the bobbin nest into it's place just under the slide plate, like a class 66?