I have subsequently found out that there was only one pub in Upper Dicker - The Plough. In the 1850s it was owned by Edward Monk & Sons of The Bear Brewery in Lewes
. The East Sussex Record Office in Lewes has all the papers which relate to The Bear Brewery, so this could be a good source of information.
I have also heard that there is a book by L Smith
called A History of the Dicker
(2003) which may be useful.
Information about the previous owners and occupiers of the property could be found by using the Ordnance Survey 6 and 25-inch sheets, c1875-1930s, parish tithe map, c1840, land tax assessments, rate books, valuation lists, licensing registers, locally proved wills before 1858, electoral registers, 1832-1992, census returns, 1841-1901 and local directories, 1855-1938.
For a novice like myself, the amount of research sounds quite intimidating.
On the plus side, I guess that with this amount of data available,
I should be able to find something.