Re: Greetings and ask for advice

That is a fine looking project.
"Uncovered and used" for how long? The collected rain and snowmelt is your enemy here, is there a clear internal waterline showing how high the boat has been filling up? Anything at or below the line is under suspicion though not convicted. You'll want to poke it all over with a good awl to see where any punky spots might be hiding under the paint. Check the frames too.
Once you have an idea of where any bad areas are, make templates of the existing shape before cutting them out so you have a reference to shape the replacements. I'd lean towards replacing bigger sections as opposed to trying to patch little rot pockets, as David G said the spores can travel pretty far.
Steve
If you would have a good boat, be a good guy when you build her - honest, careful, patient, strong.
H.A. Calahan