You can't see the autopilot drive unit clearly. It's kind of like my wife's new black puppy. It's above the stern fuel tank. The mount is to the right. See those four shiny bolts?
The diesel tank in the stern is the stock water tank. I shopped for a proper larger tank and couldn't find one either through Hunter or any of the manufacturers recommend by West Marine or that I found on line. This tank has been holding diesel for 12 years so I decided to fix the problems I had with the installation and make do. I double sealed the outlet at the bottom so it won't seep or drip. I also did the same to the vent on the side of the tank. I put a pickup in the top with a shut off. It leads to an electric fuel transfer pump via a inline Racor separator. Then the fuel is pumped to the factory tank. The fuel is filtered a second time by an identical separator leading to the engine. The first filter is seen in photo #50.
I fuel up by always using the stern tank. In that way the fuel is kept fresh in both tanks. They both are connected in tandem to a dual outlet vent system with 'Whistlers'. The stern tank, now vented out of the top of the tank, has fuel returned to it from the factory fuel tank when it's full. An endless loop, so to speak. The drawback is the fuel fill is at the old water fill location so if you overflow during fueling, the fuel ends up on the cockpit floor. Putting the vent in the right position should prevent this mess in the future when we return to fuel docks*. Both tanks have a fuel gauge sending unit (matched) and display on one gauge at the nav station using a toggle switch in the panel that also runs the refer components. It is a three position 'bat-wing' model, (on)(off)(on) so it's spring loaded to be normally at the center position. I push it to ether side to energize the respective tank for a reading. All of the switches are from Blue Sea Systems . The transfer pump switch is on the control panel.
*It works-so far. 10-9-3. And on 8-2-4. The stern tank is totally full. As soon as the whistle stopped, I stopped fueling. Didn't spill a drop. Canada, here we come.