An unusual idea on GGG marks
I may have found something that relates to your teapot, sounds remote, but not a bad association in my opinion.
First read this:
M. H. Goodwin's Grand Grease Juice. In July 1855, M. H. Goodwin received copyrights from the NH District Court, for the trademarks G. G. G., G. G. G. or Q of F, Goodwin's Grand Grease Juice and Goodwin's Grand Grease Juice of Quintessence of Fat. Goodwin called G. G. G. 'The Great American Preparation of the Establishment, Growth and Beauty of the Human Hair.
Dave Bowers recently discovered that while Goodwin held the copyrights, the products were not distributed by him. By 1856, Charles H. Goodwin, a relative of Exeter was advertising patent medicines, and was listed as an apothecary in the 1860 New England business directory.
Among his products was G.G.G.G., a 'breath perfume.' A classic mark! "Use/G.G.G." bold XF mark on choice brown VF/XF 1853 Large Cent.
NH) Goodwin's Grand Grease Juice. As above, "Use/G.G.G." bold XF mark on choice VF 1853 Large Cent.
8326. (NH) Goodwin's Grand Grease Juice. As above "Use/G.G.G." bold VF mark on 1853 arrows Half Dime, dark Good.
8327. (NH) Goodwin's Grand Grease Juice. As above "Use/G.G.G." bold XF mark on sharp toned XF 1853 arrows Seated Liberty Dime.
8329. (NH) Goodwin's Grand Grease Juice: Use GGG & GGGG. The longer variety
"Use/G.G.G./&/G.G.G.G", very bold XF+ mark on choice brown VG 1847 Large Cent.
8330. (NH) Goodwin's Grand Grease Juice Use GGG & GGG UNIQUE Variety. Only known specimen on 'Millions For Defense' Hard Times Token: "Use/G.G.G./&/G.G.G.G." bold XF on choice brown Fine 1837 HTT. Unique on HTT.
These items are all USA coins, so is it unreasonable to think that the GGG you refer to could be COIN SILVER of the time. Notice that the Items are Silver and although it may not be a connection to a maker, it sure can be a connection to a Copyright to the maker or owner of the Copyright at the least. You can find this on a site, that has a mess at the top of the page, scroll down the page, you will find these items and the items are finished sales, but they do have other new pages and are even on Ebay.
I realize that a copyright and a trademark are different, however in the mid 1800s there were many copyright, and trademark issues being argued and laws being made to contend with them.
Coin Silver was sold in a great abundance during that time, and many watch cases were made of coin silver at that time also, along with PURE Silver to make other items. Your teapot may fall into this category. Remember, this is American silver I am referring to, but England, I believe did the same at about the same time. I'm not sure of this detail, but I think I remember it correctly. You may want to search about coin silver and the like, to get a connection to silver pieces being produced from this material.
For another idea about GGG hallmarks click here