Georgian christening knife

[Granmaa]

Here is what I assume to be a christening knife; it is 20cm long with the owner's name engraved in the silver blade. There is a date letter on the haft, I can see the crown above the letter in a rounded cartouche so it must be Sheffield 1799-23. I'd say it is the 1808 P but I'm not sure.
I'd like to know the maker IN, and what you think the date letter is.

Miles

[dognose]

Hi Miles, Could it possibly be the R of 1813? If so, then Joseph Nowill would be a good fit, it was quite usual for a christain name begining with J to be represented with an I, regards Trev.

[Granmaa]

Yes, it could well be the R; I can't see anyone else more likely, so I'll go with him for now.

Miles