Coffin in a Day

After making a couple of standard toe pincher coffins, I wanted to make something a little more modern. It's modular to store in the attic or garage.

Supply List:
2 - 8' 2x12
2 - 8' 1x2
4 - 8' 1x3
2 - 8' crown molding
3/4" plywood for arches
1 sheet polyfoam insulation
2" masking tape
Pint of black latex paint

Extras:
piano hindge
white silk material
chrome towl rack
2'x4' hard board

The interior dimensions are 24"x72" and lid arch dimensions are provided.
The bottom is left hollow, I place blocks on the interior to hold a precut 24"x48" sheet of hardboard.

I've included the autocad file to pull the dimensions from.