My DS-1 has mahogany seats -- I believe they're originals dating to 1961 -- that show evidence of several repairs over the years to hold together the joint between (a) the two relatively short (3' or so) seats running out at mid-ship from the centerboard trunk, and (b) the longer seats (5' or so) running lenthwise along the port and starboard sides that intersect the mid-ship seats described above.
I'm currently inclined to prop up the joint with a mahogany or pressure-treated T-shaped post, perhaps anchoring it to the floor with fiberglas using my West system stuff, but would welcome any other proven solutions to the problem.
Chuck Goodrich (good5buck-at-attbi.com)