You can check the quality of your main stringers in a couple of ways. The main stringers form the boundaries of your bilge. One way to check your main stringers is to put a wrench on the lag bolts that secure the engine mount hardware. It the bolts turn in the wood without tightening, then the wood has lost its integrity. My boat has one lag screw that won't tighten, so I know my days are numbered.
Another way to check the main stringer is to drill a small hole through the fiberglass in an area that you are suspicious of rot. Drill the hole, and examine the wood chips that result. If the shavings come out wet and spongy, or if water runs out of the hole, you probably have a problem on your hands.
The floor probably could be repaired at the week spot, by cutting a peice out, creating a flange, and adding a new piece back in with screws and glue.
Noticed you did quite a bit of work on your 87 Comp ts6m. I have tried to look at all your photo's but clicking on the old links don't bring up the photo's.
I have an 87 Comp ts6m as well and have a small soft spot just in front of the rear seat on the port side, the rest of the floor and ski pole don't budge. Could this just be a soft spot in the floor that I can replace? How do I go about checking for bad stringers?
Any help would be greatly appreciated.