A good, accurate discription of the wall construction. We got to see this first-hand at the FR plant in Millersberg, IN.
If wood is coming out of the screw holes, it could be from wooden backing blocks inside the wall used as an anchoring point for anything attached to the exterior.
Is it possible to inspect the inside wall in the same area by removing panels inside the cabinets?
Have you inspected the roof for recent repairs or have you identified the source of a leak? The most likely location is where the roof meet the end cap.
Nights camped in 2013 - 55, 2014 - 105, 2015 - 63