Try US Yacht Cushions
They're in St. Petersburg, FL, and made cushions for Hunters up into the early 1990's. I needed new fore and aft berth cushions for my 1998 H260. They didn't have the patterns, but they had tons of material and foam, so I sent them my cushion covers, they traced the patterns from the originals, and gave me a quote. They quoted for replacement 3" and up-sized 4" foam. I think the 3" full set was about $500 - high because the foam price has sky rocketed because of the price of oil. They did great work. Their number is 727-528-9644.