I've walked through that church yard a few times and thought they were comemmorative plaques or a grave but could n't understand why only the year was put on. There are some serious size monuments in that churchyard. Some were still very readable the last time i went. My geat grandfather lived in bilston but was a stonepit miner. He died when a load of stone came down on him in sep 1861 but he's buried in a public grave in bilston cem and also a child from the marriage. I had a walk through this churchyard afterwards. Saw a load of the stone monuments, wondered whether he'd pulled some of that stone. If you google st leonards church bilston and grave vaults/stones you can see some of them and also the inside of the church. The church usually takes place in september and you can usually book a tour of the tower. Apparently st marys in bilston have some of these iron slabs.