Would it not be worth having a walk in the cemetery and seeing if there's any members of staff there , who could help you?
I work in a cemetery myself (not Redcar and Cleveland so it could be different) , and if a member of public comes to me asking to find a grave - i'll either find it for them , or ring our office with the relevant details. Our office then supply me with a grave number - and i then locate the grave .
I don't know if Redcar and Cleveland have staff in their cemeteries through normal working hours , but maybe it's worth a try?