1969 wiring question

[lahrfarm]

I am in the process of gutting a 1969 Ambassador. Interior is out, and I ended the day removing the interior part of the original ‘69 A/C. I have a few questions this brought to mind. First, the skin running down the center is a formed piece, not just flat aluminum. The old A/C leaves a 23” gap in this piece, anyone have a good idea for filling that gap. More important, my Ambassadors wiring runs over the ribs, using the formed aluminum as a path. The ribs do not have a recessed place for the wire. If I use flat skin, there is no path for the wires. I thought they all had a recess in the ribs the wires could pass through. I am assuming drilling the ribs is not an option. I will post a picture when I can take one, I’m not sure if this will make since without a pic. Thanks