I went to St Paul's the other day as I was nearby and I have some ancestors buried there.
I wasn't expecting to find anything, but to my surprise there are still quite a few gravestones there, most of them legible. I was noticed by Dennis, a very helpful gent who was on duty at the church to assist visitors. He produced a book containing transcripts of all the headstones, including some which no longer exist. Two were for my family, which was a very pleasant surprise. Sadly their stones were not among the surviving ones but I came away with much more than expected.