Something on the cheap that might work for you for your battery box is at True Value I found little black plastic garbage cans for $2.99, ones like you'd use in an office or bedroom, actually pretty nice thick black plastic that cuts with a box knife or tin snips. Making a small case out of acrylic sheet and using Dap plastic adhesive to glue the black plastic to the outside, it looks similar to black shrink wrap but is more rigid and looks pretty nice, the plastic has kind of a black matte finish, not glossy. I think it would be possible to make a case out of 1/4" plywood and cover with the black plastic stuff for a decent look, some protection and waterproofing.
Yuba Mundo w/BBSHD
Specialized Hard Rock w/9c clone, statoraid, hubsink
Trek Fuel 90 w/BBSHD
Above all run on 14s4p 52v li-ion
Ecobike folder 36v
Currie Flyer scooter 24v on 24ah of SLA
Every trip made with electric bike is one less car trip, saves money, no toxic fumes, less noise, less impact on roads.