Anyone ever heard of gold fill being marked as gold shell?

[glitts]

Good day everyone. I was recently shown a ring (seen here), it is a beautiful setting aside from the rough prongs. The inner band is marked with the drawing below-it looks like 2 fish hooks facing each other, then it is stamped "1/20 14K GOLD SHELL".
I have a few questions, an interested to hear any responses; first was gold fill or plated ever marked as "gold shell"? Second, is anyone familiar with this hallmark? And third if jewelry was marked gold shell, where and what era? Cant wait to hear what everyone has to say.
Thanks so much for your time, and don''t forget to check out the photos below.

Best Regards-
Melissa

 

[cinnabar]

Source: Webster''s Unabridged Dictionary 1913

Gold shell.
(a) A composition of powdered gold or gold leaf, ground up
with gum water and spread on shells, for artists'' use;
-- called also gold paint.

Sounds like the sort of thing they used to decorate statues, as it would be too fragile for jewelry use?

 

[PhillipSchmidt]

Perhaps it is rolled gold, but by the look of the wearing it might just be gilt.