Recommend trying Great Lakes Boat Top Company, 15 Quality Cir, Vonore, TN 37885. I got full camper canvas and cockpit cover from them for my 2002 322. https://greatlakesboattop.com/ Their make/model selection system lists a 2018 278 SS, but their pulldown for year does not go past 2018. Might give them a call...1-877-867-7861