I asked about filling a hole in a concrete coping stone some time ago. I concluded that the potential for making a mess was too high so I called in the professionals. What has been done is very solid indeed but with a slight difference in colour and a rough rather than polished surface.
Without spending any serious money, is there any product that could be used to created a neater finish? Conveniently, the concrete repair is slightly indented and slightly rough, so I suspect it would provide a very good key for a skim.