IIRC we have discussed this before and found that some boats have 1/4" nuts imbedded in the keel, while on others the plate is simply secured to the keel with wood screws. Mine has nuts, but two of them are gone, so I rebuilt the area and went with wood screws. I think the caulk is probably the thing that really holds the wedges in place. On my boat, there was actually only one wedge when I pulled the board out.I thought there was a metal plate molded into the bottom of the keel on hte 23 (1977-85) that those bolts screwed into? (I know the 1982-85 DS II had sheet-metal screws to hold the plates in place) Possible it has corroded enough around that bolt to prevent the bolt from threading in? Perhaps a threaded insert could be installed to restore the threads, a brass or stainless-steel one would seem best. In the drawing below the bolt holes are there but not the bolts, those plates are on the bottom (outside) of the keel.