[Dave Hirshberg]

Well, aside form the floor, box stringers, keel board, transom, port and starboard bulkheads, fuel tank lid and the hatches there's practically no wood at all. But don't worry too much about all the wood, it was and still is an integral part of boat building. Fortunately SeaCraft did it far better than other builders at the time.
I have a hunch that the wood you are finding in the keel area under that patch is actually a 3 inch keel that runs the length of the boat. Do as everyone stated above. When you fix it for good you may have to cut a small circular access plate above the repair site in the fwd fish box to get at the keel and glass form the inside. But only if you can't get thru to good wood from the outside.