If I understand your question correctly, the tank leaked out under the fuel sender? Looks like a snake river sender, does it even work? On our boat we had the same sender with better access, and just before we bought the boat the PO had the fuel polished. The polisher did not re tighten the screws. I found it before refueling as it would have made a real mess. It looks like you could get a short screw driver in there to reseat the sender. If not a right angle drill with a bit. I ultimately replaced our broken sender with a wema and a round gage.