Toyhauler fuel tanks

Can anyone send some pictures of how the fuel station and generator tanks are mounted? I bought a 2007 387 skyline and it had no tanks. I couldn’t find anything on how they are supposed to be mounted so I connected the sensors to them and they marked empty when the sensor was upside down so I had thought I had figured it out that way. So there I go installing the tanks and I welded some brackets.. etc and after everything I was still unsure because I figured If the tanks are filled from the bottom the gasoline is going to have to be pressurized to fill up! 

I didn’t see how it could have been filled from the top since there are no holes in the frame and didn’t want to make one since it can weaken the frame. But if that’s how everyone else’s is I’ll make some holes and reroute the filler neck! If you have any pictures from a 2007 skyline that’ll be great or any other trailer cool too!