few tank questions

[stockgp]

i've noticed the left side tank is hanging down pretty low in the front, and neither filler neck is attached to the bed.

my brother (the previous owner) told me he suspects the left tank to be an aftermarket replacement. why, i have no idea.

i went out and took a few pics, but just what i could get without jacking the truck up. it appears the tank i solidly strapped in. i was unable to push it up by hand. am i missing something?

as for the filer necks, the left one clearly has no way to attach to the bed. and the hose is clearly kinked and gets worse if i actually put the filler neck in the fuel door.

the right one has a flange, but it does not appear as though it would be able to bolt to the bed. what am i missing with these two? it's difficult to even get gas to flow into the left tank. the right tank fills fine, but has a crack in it somewhere so i need to fix the left side