I have the floor up on Tia Maria and the fuel tank "lids" are steel plate with maany bolts round the perimeter. Does anyone know what the rest of the tank construction is? has anyone replaced these lids? I could not imagine replacing with steel as drilling that many holes through heavy plate wuold take eons! any suggestions? Mine are scaling rust off at a fast rate. I was thinking heavy layup of epoxy/glass over plywwood.