Postby dognose » Tue Nov 10, 2015 5:33 am
I agree with Steve, this is the mark of Stephen Smith & Son (as a firm, often confused with Samuel Smith & Son) who were taken over by Mappin & Webb in 1886.
I think what has happened in this case, is that the item was bought in and Stephen Smith & Son have overstruck the existing mark. If the original mark was struck deeper than Smith's, then part of Smith's mark may not have taken on the rounded surface of the item, that is to say, if the original stamp was was deeper on the right, and the secondary stamp was deeper on the left, then the resulting effect would occur.
I know, clear as mud!
Trev.