I went in search of my grandmothers grave at Ford, this was about 4 years ago.
Outside (at the time) was a notice board with a phone number. I think it is manned Mon-Fri.
I called them they gave me lots of information about the grave including the names of people I had no idea were buried alongside my nanny.
If you call them they may be able to advise when a groundsman or member of staff will be on the site.
My own nan was also buried in AS, it took us a while too, in parts there appeared to be a pattern but in others it was quite random.