40 fordor Deluxe Package tray

[my40ford]

ordered a interior kit from Cartouche, but having trouble with how the rear package tray goes. It is just a piece of pre cut fiberboard wrapped with cloth, so is there a piece of wood that it is supposed to sit on? i see where there are 2 previous nail holes in the metal frame but it seems to flimsy to just screw down because it wouldn't be flat and sturdy. I will try to upload pics this weekend.