The block you see in the front is to screw down the hatch door, The spacer on the door is to fit under the landing gear block and it fits between the fuse sides where you are supposed to glue it in, The tank floor also needs to be trimmed on the sides then screwed into the mounting blocks, Actually got my camera inside the fuse to take the pic but you can see how they are mounted where the the tank floor is sapposed to glued, Also the blocks I put in are to hold the tank centered so it is a pretty snug fit between the blocks. Soory if this sounds confusing, I stinck at explaining this stuff but you should be able to understand it in the pics.

Dauntae