Strange Fuel Tank

[0005K]

Terry
Yes, I believe that there is a thin channel in the cross bar to accept the bottom of the cardboard trim piece.
I believe the angle is so the straps retaining the tank are secured at a right angle to the cross bar. The angle for the side brackets appears to be about the same as the angle of the rear surface of the installed fuel tank. Yes, the lower brackets are bent by design to position the cross car bar in the correct attitude.
My car also had some heater hose pieces cut lengthwise pushed onto the forward edge of the cross bar - to perhaps cushion the tanks. These would be hidden by the cardboard , once it was installed.
If you know of a reasonable source for replacement cardboard, I may consider fabricating some replacement boot trim. My car - well used - came with one horizontal plywood piece which I think goes over the spare tire. I have to replace that also due to battery acid damage.
Dick