How can I identify this hallmark?

In a box of junk from my grandmother’s house I came across an old silver tray. It’s pretty tarnished but would probably clean up OK and look quite nice.

Out of curiosity I was trying to see if I could find a bit more about where it came from, by the hallmarks. However, I assume because it’s not solid silver, the marks don’t seem to tally with any of the British Assay Office marks I can find on the internet.

A picture would be best I suppose, but failing that I will try to describe them. That’s a bit tricky, as they are rather worn.

There are five oval or shield shapes, of which the middle (third) one is longer than the rest and contains the letters ISG (or possibly ISC).

The remainder, from left to right:

  1. Totally illegible, but doesn’t look like any of the assay office marks (lion, anchor, whatever). Best guess is it looks a little like a Gothic-script F but with a loop instead of a straight upright.

  2. A lower case p, but with a very short stem.

  3. ISG, as detailed above.

  4. A greek capital Omega, as far as I can make out.

  5. A Gothic script capital S, a bit like the one here: (click “1773-1900”, then it’s a similar font to the 1824-1849 series)

Anyone got any clues?

Do the “F” and “S” look anything like the marks on the pic of Baltimore Silversmiths (right column, 5th one down)? Don’t know how that relates to the rest of your marks, or the lion in the pictured mark, for that matter…