If you can post links to these images you are looking at someone may be able to tell you if they are the same place - I don't know the area.
If, as I suspect, this was a church burial ground (even though its not within the church grounds) then I'd say that the parish register where their deaths were recorded (the links I gave) will be the only record in existence.
Had they been buried in a civil cemetery (owned and run by a local council) then there would be a cemetery register of burials and a grave register, but in my (limited) experience parishes (for any flavour of religion) didn't usually have such 'extra' registers. Given that, its unlikely that anyone will be able to tell you exactly 'where' in the cemetery they were buried.
Do also bear in mind that the 1920s and 1930s were times of extreme hardship for many families and the chances of there being a gravestone in the first place are greatly reduced.
It looks like the church at West Cornforth was demolished in the 1960s (it was falling down due to mining subsidence) and a replacement church with the same name was built at Coxhoe, so if you are going to enquire with the parish it would be Coxhoe you need to contact
http://www.rcdhn.org.uk/churches07/churchcontact.php?chid=134Boo