We also have a Itasca Horizon, 2005. We were in Colorado when we noticed both our front fenders had broken free from the brackets that held them in place. The brackets looked like they were held with some type of bondo. We went to several places and were told to take it back to dealer, well we were along way from a dealer so we went to the hardware store and told them our problem, we left with a bottle of Gorilla glue and some medium size adjustable clamps (the type your can use to go in either direction, with a squeeze handle). Put the Gorilla glue (we used a toothbrush for the Gorilla glue) around the bracket and clamp to the fender you may need to use small blocks of wood to help support the clamps.
Remember the Gorilla glue really expands - we probably used a little too much, but we wanted it to hold. It swells all around the bracket and on to the fender. It dried overnight, but we let it set 2 days while we were in the campground. The Gorilla glue will turn yellow when it dries, but we just spray painted it black. It has been holding for 5-6 years now with no problems. If you have any questions you can email me at
diane98@yahoo.com. Good luck with your repairs!