Okay I had a Gen. Contractor friend ask for a bid on this one. I have no idea how old these walls are but they have no geogrid and probably no base, just mortared limestone. The only part I'm concerned with is the part that is failing. I'm planning on ripping the upper wall down and putting it right back up. The customer is repairing it because he is going to be selling the house. My main questions are if it would be more cost effective to use new rock, or try to chip the mortar off the old stones and replace with new mortar? I will be digging down and putting in a base on the part that I am redoing, but should I need to do geogrid, and if so, how do I tie it into a mortar stone wall? I have quite a bit of experience with srw walls, but in this application it would not work, because home is surrounded with limestone walls, even right in front of where this wall is being repaired. Wall measures 120 linear feet and roughly 3' high. Marcus and Treedoc your replies would be greatly appreciated, along with others that might some experience.