For those of you who use the wooden bottoms of the paper-covered boxes as soundboards, what do you do with/about any markings on the bottom?  For example, on the Arturo Fuente boxes, there's a "burnt" scroll shape with full brand name and serial number.  Could I sand it off without damaging the bottom?  I really have no idea how thick the layers are in the plywood on those.  

I also have an Aroma de Cuba mi Amor that I plan on using in such a way that both the top and bottom would be visible, but the marking on the bottom would show upside down.  So do I find something to cover it up, sand it off or just leave as is?  (Basically, I'm using that box to recreate the Cigar Box Harp as found in a previous post on this site.  The box would be on it's side with both the top and bottom being used for soundboards of a double-sided harp.)