Andrew Nethercott Antiques has dated this Victorian Nautilus Spoon Warmer to the 1870s.
A very rare design I have seen no record of, a dramatic variant loosely based on the nautilus shell.

The coiled and ribbed shell forming a near spherical spouted vessel
Makers number stamped to one foot
Electro plated nickel silver (EPNS - hard metal not soft Britannia metal / pewter).
In excellent condition with no damage or repair, little wear to the silver surface.
Overall width 6,1/2" or 165mm, weight 742 grams
Andrew Nethercott Antiques has dated this Victorian Nautilus Spoon Warmer to the 1870s.
Works of art, collectables, scientific and decorative antiques from the 17th - 20th century
You can view the stock and full dealer information on the Andrew Nethercott Antiques Profile Page