Hi caroline, all 104 catacombs are bricked up. In all the years us kids hung around inside st james cemetery we never seen any vaults that had any kind of door. My father and grandfather grew up facing the cemetery, they never mentioned vaults that you opened with a key I cant imagine why anyone would want to open the vault?I don't think they went back into the walls that deep . You can still see these walled tombs as you walk up the ramps where the horse drawn hearse would have entered the cemetery via Upper Duke street. Some of the tombs along these slopes have gravestones in front of them, Ive seen Sir William Browns gravestone, he the founder of William brown Library in Lpool city centre. If you any pics taken feel free to ask me. I don't know if you live in Liverpool.