I’m not convinced about Timothy Ley, John. His mark was LE in conformity with the law requiring the first 2 letters of the surname to be used. I prefer Nathaniel Lock (Grimwade no 1948). This has a key above which may well have been lost over time on your porringer. I would also go for 1713 as the date, but I always have difficulties with this cycle as it’s not immediately obvious what the letter is supposed to be.
As far as wow factors go I think that at that age they are all much of a muchness, unless it’s Lamerie of course!
Phil