“Hi Tom,
I have a brochure that shows the tank size at 245 gal. for the main and 50 gal. for the auxiliary tank.
The deck fill plates typically mimic the arrangement of how the tanks are in the hull with the aux. tank forward and the main tank aft.
Your zinc’s are bolted into the hull. This is why the bolt just spins. You should look inside and remove any nuts holding wires.
The fasteners used for the swim platform braces are #14 screws for the bottom into the hull and 1/4 – 20 bolts up at the platform itself.
Let me know if you have any more questions. Thanks,
Walt “