Welcome to the Forum.
I read the hallmarks as London 1835. See: http://www.925-1000.com/dlLondon.html
The watchcase maker is likely to be Samuel Strahan who at this time was working out of 36, Whites Row, Spitalfields.
If you were confused by the lack of a point at the base of the dateletter surround, it is because, on smaller items of this period, a rounded base surround was used.