Thimble unknown maker

I have just registered with your site because I have a silver thimble and I cannot find the maker. The Hallmarks are quite poor and my camera isn’t up to very close work but I will try to describe the marks as best I can.
The first mark looks to be a mis-stamped 8 the top circle is there and both sides of the bottom circle but not the base, hope that makes sence. The next mark(I assume the maker) is SF in a circle. The next mark is the british lion. The next mark is very worn but could be a shield, it’s that shape but there are four “bits” sticking out two at the top corners and two near the base. The last mark is a lower case “d” I have added a photo but I do not think it’s good enough to help. Sorry my first request is not straight forward but hopfully someone may have an idea.
Letter.jpg
sf mark.jpg

Hi its British silver, hallmarked London (the shield is the London mark with the head of a lion) 1899, SF could be Samuel Fenton.
Looks from what I can see as a nice Item and would appeal to the sewing collecting fraternity

Thank you bluerinse for the info, I received a similar answer over last weekend from another source, they said London, which apparently is unusual, and 1899 but they said could be Samuel Foskett. The thimble is in it’s original box, leather covered wood but the leather is a bit worse for wear.
P5230007.JPG

Here’s some info on Samuel Foskett:
thimbleselect.bizland.com/foskett.htm

Thank you snuffer, that was brilliant.
If only items like this could tell a tale.