I had this happen on our 2014 Bighorn 3010. See photo. I had enough room to move the whole assembly straight down about 1/2 inch and put new fasteners in. Alternately, you could mount an oversized plate behind it and put it back fastened to the plate. If worse came to worse you could drill all the way through the wall and use small carriage bolts with fender washers pushed through from the outside to put it back together, but that wouldn't be very attractive on the outside. I think the key is not to get too far out of level or plumb with the cables when reattaching. Sorry, no photo of the repair... Good luck.