I have house built around 1900 that has solid masaonry construction with cement render over the bricks. The render has cracked and blown in places. It has also been patched in many areas by the previous owners. Will I able to fix the render by fixing the blown patches and using some good paint or will I need to hack it all back to brick. I am quite nervous of the second option as I am worried about doing a lot of damage to the bricks. Any advice would be most welcome. Please see attached pics.