I have a silver sauceboat made by Joseph and John Angell. The date stamp seems to indicate 1814 George III. According to Grimwade, Joseph and John only established their mark in 1831. I am a tad confused.
The London date letter for 1814 is “T”. This is “q” and in combination with the uncrowned leopard’s head indicates 1831. I think you may have been looking at a Birmingham table instead of London.