An alternate idea
Dave, I don't have the patterns, but on my O'Day 20, after getting a bunch of crazy prices on having the cushions done, I just went to Garden Ridge and bought some outdoor cushions. I was able to redo the entire boat with lounge chair cushions for about $250. Is it perfect? No, but it looks pretty good, and now, when my kids make a mess and ruin a cushion, I'll just spend $20 and replace it.