Cabin fumes

[mikseymono]

Back on it now...lockdown induced...

So, I have been looking at the rear fuel pipes/tank again.

A couple of questions:

1 - There is a rectangular metal, section about 400mm x 300mm that sits (welded?) on top of the fuel tank. See photo...is this normal? Or has someone in the past cut this section of the boot to access the tank/pipes?
2 - On the filler neck I have labelled two pipes A and B...what are these specifically please. These two pipes feed back to the tank and are severely pinched at the location indicated by the red arrow. I can't even move them when I undo the clips....properly squeezed up there.

All hoses are tight on and no leaks.

Just want to put it out there before I start to go deep......

Thanks

M.