Hi Willi,
I saw an earlier post of yours suggesting that Brunswick Square Burial Ground was in Westbury. In actual fact it's in Central Bristol. I doubt there will be any gravestones left as the Burial Ground in Brunswick Square was purchased by the Presbyterian Society in 1768. The last burial took place here in 1963, and in the early 1980's the Burial Ground was landscaped, and the headstones removed by the City Planning Department to provide a public open space.
However, I believe there are one or two left, so I'll go and have a look this weekend and at least I can send you a photo of what remains of the burial ground next to the church if nothing else.
If you send me a PM with your email address, I'll send you the photos after I've been.
Martin