When I bought my Northtrail TT a couple of months ago, I contacted Heartland customer service and gave them the VIN #. They were able to look up the build date etc. and sent me a copy of the schematic for the back wall. It showed where there were wooden braces built in during construction. Forwarded it to the dealer and while they were prepping the trailer, they added a rear-mounted ladder using the wooden bracing - a lot stronger than the aluminum frame. I think it was only a couple hundred bucks total including install.