"Gambia" is a maker's mark which appears to have been handed down in the Greaves family in Sheffield. The first mention I've found of the mark is in association with Abraham Greaves, Pea Croft, who is listed as a maker of bookbinder's, gardener's, tailor's, goldsmith's, &c. shears in 1787. The next mention of the mark I've found is in 1825 and 1828 Sheffield directories, associated with a George Greaves. He's listed as a manufacturer of garden, tailor, tinman and brush shears at 54 Scotland Street. And, in those same directories, Isaac Greaves is listed as a saw, file, and edge tool manufacturer at the same address. Next, an 1847 Isaac Greaves advertisement lists a large number of types of shears he manufactures and states: "N.B.-All shears manufactured by him are marked 'Gambia.' " Finally, in 1911, the trade mark listing for Joseph Peace & Co., Ltd. lists a number of products and continues: " ... also manufacturers of the celebrated 'Gambia' shears formerly made by Isaac Greaves."
Working dates for Isaac Greaves, or a firm using his name, stretches from 1825 to at least 1905, and the firm appears to have been incorporated into Joseph Peace & Co., Ltd. by 1911. He is listed as a saw maker from 1825 to 1828 then from 1849 to 1855, so those periods may be the most likely times your saw was made. But he may have marked and marketed saws under his name at other times. For example, in 1856 he is listed as an edge tool and shear manufacturer as well as a dealer in saws, files and steel. During the remainder of his tenure, he is variously listed as a maker of edge and joiners' tools as well as a number of different types of shears.
Interesting that a mark for shears would show up on a saw. Have other folks seen examples of this?
Hope this helps.
Don McConnell
Eureka Springs, AR