I was gifted a 1910 White Family Rotary with a beautiful treadle cabinet. The machine is in great condition with decals 98% intact. The cabinet has some damage. It even came with purchase papers, booklet, and attachments.
Just went on Ebay and found a complete attachment box. Inside the box was the chain stitch throat plate and spider. The outside of the box has "White - Family Rotary." If it was not for this thread, I would have never known about the spider or what they look like. Thank you Mizkaki for the photos. Now I can sew knit fabric with the chain stitch spider and throat plate.
It took me almost a year before I found a good shirring attachment for the Singer Style 11 puzzle box that was made for the Singer 15-30. I also had to purchase another complete Singer puzzle box to get that shirring attachment. Sometimes you have to buy an attachment box with attachments to find that one piece. It is well worth it.
Keep looking. That's part of the fun and frustration!!!