Hi. Need some advice please re dampcourse found 3.5 courses below ground. This is the back of my Victorian terrace. Previous owners had taken out back window and inserted a door and laid a concrete path to the door. The floor joists inside this door were rotting which led me to investigate an air brick, which I found buried under the door threshold. Having taken up some of the concrete and dug a trench, I have what you see below. I will have to replace some blown bricks and completely repoint the unpainted area. My question is, what would be your course of action here? Should I dig out all the soil and put a retaining wall in along the red dotted line to hold back the fence, dig another course down and fill with 20mm gravel to one course below slate. Paint wall above slate. Or retro fit a new plastic DPC somewhere around the green dotted line, back fill current trench with 20mm gravel, building trough for airbrick? Or something else? Any advice appreciated. Many thanks