Stringers, is the juice worth the squeeze?

[MR nova @#25]

I just removed the cabin floor from a 1985 Tiara 3100, because it was soft. 1/2 plywood glass on top bare plywood underneath. My plan was to remove the plywood stringers and bulkhead and redo it all in coosa. After I remove the bulkheads, I saw the stringers are literally an upside down hollow box with glass over the top.
When you hammer on the stringers there's no dead spots or delamination. I ran a camera down the length of the stringers the woods black but its intact. My concern is what benefit will I gain by removing solid stringers from a cabin and replacing them??

 

[Scott Danforth]

do some test drills. black is usually black mold.

not sure coosa is worth the squeeze. simple plywood lasted over 45 years.

 

[MikeSchinlaub]

I agree coosa isn't worth it. $400 a sheet, and either do every scrap of wood structure or don't bother.