I just had to repair the mounting of the rear top bracket on my Excella. There are 2 screws that should go into the rib and the 3rd screw just hits the skin. Well on mine the skin area had been dented and repaired, right at the vertical skin seam near the bracket mount. Well when they re-riveted the seam, they did a crappy job. Poor riveting of seam, that they gooped up with silicon. When they reinstalled the awning mount they missed the rib, so all 3 scwres were just in the skin. The bracket was loose and had an ugly mess going on. I removed the offending rivets, and goop, and pop riveted the seam with Vulcum. Filed the holes from the crummy bracket mount job, will pop rivets. Placed the bracket on skin and drilled holes for the 3 screws, 2 into rib. Seeing as the rivets I used for filling the screws holes now fell under the bracket, I had to grind reliefs in the back side of bracket to get it to lie right on skin. Used a Dremmel type tool, to grind the reliefs. Then I sealed up the head of the pop rivets and screwed the bracket in place. Fits much better, and now 2 screws have good bite in the rib. Plus the seam fits together much better than before.