Hi Ann! Do you sew with her? I have a Singer 15-91 with a pot motor. Sews like a dream! I've never tried a treadle, but love vintage sewing machines. Just love the Sphinx decals, it's really unusual to see a sewing machine that old with the decals in such great shape - the whole machine looks in remarkably good condition for that matter! Do you know her history?
Your machine is beautiful! I sew on a 60 year old Singer 201k . I would love a 15-91: they are meant to be the best for FMQ.