Hi Hemster,
Mart is right, these are little salts and would originally have had glass liners.
You did well to pin it down to October 4th 1880, the best I could come up with was this re the makers:
BRIDDON BROTHERS
BRIDDON BROTHERS & CO LTD
Sheffield
Briddon Alfred & Frederick, from 1863-1910 at Victoria Plate Works, 7 Eyre Lane, Sheffield. They became & Co Ltd in 1905 (so these are definitely pre 1905)
They are plated silver and so probably not very valuable, but they are very pretty and I'd certainly have them on our table (if we used much salt that is...). You could keep an eye open for replacement liners, but they're like hens' teeth over here.