Hello again David. I'm just holding it until you come get it, OK.
(seriously I would part with it cheap)
Now I think I understand what you want and yes, you can buy an UB (underbody) type box almost anywhere that would approximate the size of the fuel tank. They are generally made 18" & 24" deep x 24, 30, 36", etc. long. An 18"x24" should be pretty close. I was thinking of the tanks that are full length steps and that you wanted a box made to fill up that space. Check any truck supply company near home.
