Aluminum plate sandwiched in the glass ?
If you do not see the nuts and you are sure that you have no access to the area, there is probably an aluminum plate sandwiched in the glass. My former Hunter 28.5 was like that. Suggest you carefully remove the organizer from the starboard side and check it out. Check out bolt size and length as well. Port side will be the same. Using the new organizer as a template, carefully drill a small pilot hole, no deeper than the length of the bolts you removed from the other side. After you've gone through the fibreglass, you should be getting aluminum shavings coming up around the drill bit.Mark you second hole, and drill pilot hole, then use proper drill size for your new bolts. You will need to carefully tap the aluminum plate with the proper tap for your bolts.Seal the area around the holes with caulking and install the organisers.Good luck