We have a Bone China Scarf Accessory, nos, new old stock (coming directly off of the sales card from the mid 1970's).  It measures about 1 5/8" across the center.  On very close inspection it is not quite perfectly round, very close.  I am taking this off of the original sales card (assorted floral styles) which is blue.  There is a faint blue residue on the back of the holder from the blue of the card.  It is marked with this one stating it is from 1976 - 77.  The scarf place to thread the scarf through on the back is somewhat narrow therefore the scarf used cannot be to thick/wide.. In the photo I used a light cotton scarf about 12" in width.

Bone China Scarf Accessory nos Vintage