I picked this box up at a garage sale for , like $5.00.
I thought it was a Honda box, because it says "CB700" on the top. Later, I found that it is a snare drum case. So all you wandering minstrel drummers already know that these are very similar to top boxes.
I think that a little jigsawing on the innards, and most of these drum cases could become top boxes and travel the world. They sell fairly cheap online, and sizes vary.
just another thought, in the interest of economy.
i would leave some of the material near the edge, and remove the material in the center. I might leave the "bowl" area of the case as is.
tom