Great idea!
I use those rings for bobbins too. I wrap a small cloth hair elastic around the bobbin to keep thread secure. A ring of pre-wounds also go in the class tackle box.The rings also work on rulers to hang them on rod or hooks.
I just bought plastic file folders with zip loc on each side. They will fit into a notebook. I will store those specialty rulers that aren't used every day.
Love the deals right now. It's always fun to find supplies to use in the sewing room.