This is the problem with most boats up to about mid 40's in size. This is also why I mentioned a boat similar to the Symbol I owned. If you look at the photos of that boat there is a 3 person sofa, a recliner and a barrel chair! Comfortable seating in the main saloon. Even the dinette which can seat as many as 6, has ergonomic sloped back support. The fully enclosed Sundeck has a love seat and two rattan chairs which are very comfortable. Even the helm seat and flying bridge have comfortable seating! (Comfortable seating for over 25 people on that boat (31, including the dunnage boxes on deck.)--we have had as many as 35 people aboard.
Try sitting every day with a seat which has a straight back. This is a problem in most of our C Dorys, unless we have custom cushions or put strategic pillows in place.
An aside, about the 3208 engines. These were first introduced in 1967 as the 1100 series, light and medium truck engines. Unfortunately some companies put these engines into heavy duty operations on both trucks, and commercial machinery. They were to be "disposable" engines, but have been well proven. They are 10.5 liter displacement, and in that boat are natural aspirated, at 210 hp. When put up to 345 hp (as per factory, or even up to 900 hp, in some applications, they are being stressed). In this specific boat they are normally run at high torque speeds, from 1600 to 2200 RPM--and will often last as well as other slow turning engines--up to 10,000 or more hours.
The hull bottom is about 1" thick of solid glass, and a good layup. Just to correct items.