I'm pretty sure on this teaspoon, but not 100%. The hallmarks are a bit faded, but I think the marks are King George IV, S date code of 1833, Leopard head without crown, and Lion. If these are correct, that makes this sterling from London, 1833.
I do not see a maker's mark and there is a curious "PATENT 1859" clearly stamped on the reverse. I'm not sure on pattern -- Olive?
I will post a few photos.