Hi Darkcrystal
I have had a lot of experience with historical directories. Were you looking on the historicaldirectories website at all?
My ancestor appears as a beer seller in an 1879 directory for London at Alvey Street, Walworth. Bear in mind that by the time of publication, they were slightly out of date. I think the info was collected in the summer of the previous year for publishing for the following year. So the info for the 1879 directory was probably compiled in mid 1878 for 1879.
I think the website has a search engine wher you can search by keywords such as "Oxford Street" etc.
Ben