Photos as requested...
Of the completed project:
The original latch and hinges were reused. Everything else--except the mahogany outer boards--is new.
The original box-shaped evaporator was replaced with one of the same size, but was formed into an L-shaped that ran along two walls. The original compressor and condenser were kept.
The lid's insulation extends down inside the box to engage with the seals. The top of the lid is 1/2" plywood. Just about everything else is 4mm plywood coated in epoxy resin, and then covered with polyurethane paint.
Close up of the double seals.