I'll explain more here...
When I'm home in April, I can post the sketch that I sent to the foam company. But basically, it is 3" thick on top and 5" on the bottom. The corners are radiused to match the dinette wood backs. Near as I can determine without having my sketch, the radius measurement is 6 inches. The wood backs have a different radius on each end for some reason, but the 6" radius on the cushion works fine.
Once I got the sketch right, the foam company had no problem cutting it. They asked if I wanted them to make covers. So I got the fabric info from the tag on the originals, and contacted the FR cushion supplier in Indiana. I was able to purchase material from them, and sent it to the foam shop. They made the covers you see in the photos. It looks factory. We could not be happier with the results.
Costs were very reasonable. It's been a year since we did it, but I think it was around $300 for everything.
Not only are they much better for sitting, but they also feel good for lengthwise lounging too. You see the pillows in the photo. They are pretty dense, and support the hollow of my back when I sit lengthwise to watch TV. The sloped dinette cushion makes this position much more comfortable than with the vertical cushions.
I should add, even though it is kind of obvious... this means you cannot use the cushions to make up a bed in the dinette. We still have the OEM cushions at home though.
2014 Sunseeker 2300 Chevy