I am not the expert you were hoping for. I did just replace the top and side gaskets on my 2015 28bh. The sides were loose and the top was out of track on the bottom. I bought an exact replacement (AP Products 018-312-EKD D Seal for EKD Base-1" x 15/16" x 35', Black) for my sides. You'll notice it's marked 15/16" where as the track clearly measures 3/4". They had a bead of glue on the outside that held the gasket in place. I cleaned it off with plastic scrapers and paint thinner and bought Geocel GC28100 Pro Flex Rv Flexible Clear to replace it. I can't speak for the performance of the caulk but it appeared to be very similar to the origional. My top gasket was "AP Products 018-522 EK Slide-On D Seal with Fins, 1-1/2" x 1" x 40". For me that was the only fix. Luckily the quantities sold will do two changes because I bet I'll be revisiting this problem. I found all parts on Amazon.