N. Harding Coin Silver Sugar Spoon

Heavy coin silver sugar shell in a beautiful pattern I have not been able to identify by Newell Harding Co., Boston, c. 1851-1870. 6 3/4 inches long, modified shell bowl. Engraved "Sarah" in script on the reverse. Marks COIN and N HARDING CO. incuse. A good, heavy piece. Like new. While this is probably a sugar shell it just as easily could be used (and may have been used) as a preserve spoon since its shape is somewhat like later preserve spoons.