Cheers Ash.
I intend on the chequerplate stuff for the floor.
3 sheets is what I vaguely remember working it out to.
As for a fuel tank, I think I will buy one ready made. I am not good enough welding ally with the MIG, and at £1k+ for an AC/DC TIG it makes sense to just have one made. I could always make it out of steel, but I like shiny ally
Sean