Hi Iain
Section AK and all those on the Brompton map (linked by rosie99) below the central avenue in the western side are identified as common or public graves and generally do not have headstones. There are exceptions to this generalisation but the headstones tend to be for more recent burials as in post ww2. This plot is also an exception as it is a private grave with 2 (unrelated) burials, Charles Judd and Robert Gann. The record for who owned or paid for the plot is not online but could most probably be found at the National Archives.
There are 2100 plots in AK, each plot averaging 5 or 6 burials, the first at 12ft. There are still plot numbers missing from memorials on FindAGrave, this is a diminishing number though, but it is the only site that records the plot numbers. While FindMyPast and Ancestry have transcriptions and images of the burial registers, their transcriptions do not have the plot numbers.
The memorials on the Royal Parks website can be mis-transcibed, the handwriting being hard to decipher, and there are many pages missing that can be found on FindMyPast & Ancestry. Not 1 site is currently the most complete but FAG has memorials for deaths after 1997, which is when the older registers were deposited at the National Archives.
Hope this helps.
Dawn
