British hallmark with no city mark

[ag93]

I have a set of 6 teaspoons with a hallmark that has no city mark? They look early and are a light gauge of silver. Hopefully somebody can tell me more!
Thanks in advance.
Adam.

http://www.flickr.com/photos/79921151@N07/8009958980/in/photostream/

http://www.flickr.com/photos/79921151@N07/8009962064/in/photostream/

[spobby]

Generally, this array of marks indicate a London hallmark with the date letter 'F' of 1801.
The maker (sponsor's) mark may more difficult to investigate as there are many many makers marks that start with 'I' .. if there is another spoon with a clearer mark then it may help.
Regards
John