I have seem lair maps that are inaccurate by at least 20 feet, so even if you manage to locate a map (the gravediggers at the cemetery will know if one exists, or in this case it may be in the hands of the council), knowing that your particular person is in that lair is another matter altogether.
An uncle of mine was buried in "Brunton Grounds" and I cant even locate that, let alone the particular lair as no maps exist prior to about the 1880s for that particular graveyard.