Now back home I can answer your question more fully.
ACASTER, Elizabeth (, died on ?, at the age of 40).
Resided at Granville St and buried on 16 Oct 1853 in ? ground;
Grave Number ?, Section ? of St John Cemetery, Park.
ACASTER, James (, died on ?, at the age of 19).
Resided at Union Workhouse and buried on 26 Oct 1867 in ? ground;
Grave Number ?, Section ? of St John Cemetery, Park.
Notes: . Place of Birth: . Parent(s): .
The information is from SDFHS Cd of material gathered for the NBI.
As you can see no grave or section noted.
One of our old friends of Sheffield Indexers managed to photograph many plots from a number of cemeteries which included St John's Park where as already noted grave stones and been placed engravings face down... Unfortunately those photographs have been lost???? as the photographer became ill.
The biggest loss was City Road Cemetery.
Church/chapel registers have all been placed at Sheffield Archives once they are full or have reached a certain cut off date.
Hope that helps a little not an easy quest from what I understand the situation is at St Johns.