I have two teaspoons that were together with the five 1785 teaspoons that I inquired about in the message below this one. The pair have a different monogram: ACP, and very worn hallmarks. Would I be right to guess that the date mark indicates 1797?
Assuming that the date letter is upper case B (not entirely clear from your picture) then, yes, they could be London, 1797. However the shape of the punch for the lion passant suggests a provincial assay office, in which case we have the possibilities: Chester, 1789 or 1817, Exeter, 1798, or Newcastle, 1792. Without a maker’s mark to tie it down I cannot be any more specific.
Many thanks for taking the trouble to look this up. Cheers, David