There was a white uPVC conservatory on the back of the building when we bought it. There was a lead flashing along the edge of the roofline that had been cut into the original stonework. Unfortunately, this left an upside down “V” cut into the stonework. We had a go at pointing the grooves, but they were still very obvious.
We decided to replaced the marked stones with spare ones that we had sandblasted recently. By the time, these new stones have been pointed in, it will be hard to tell where these stones have been replaced.