Options

Pick the Coffin you want to use.
Coffin No LED - Has a hollow back to allow some ambient light to pass through it.
Coffin LED Strip - Supports strips up to 10mm wide, you might be able to squeeze a 12mm strip in. I didn't add any holes to the back for wires or switches since we all do things our own way, so either manually cut it, or use a negative modifier in PrusaSlic3r.

These are the backgrounds for the pumpkin.
Pumpkin BG 1 - Use this If you want to print a black or dark colored pumpkin.
Pumpkin BG 2 - Use this if you want to print an orange or light colored pumpkin

Print 1 of everything else.

Print Recommendations

I highly recommend using Ironing for all of the inserts, and I print towards the hotter end of the filaments specs.
For PrusaSlic3r I use:
Ironing Type: All Top Surfaces
Flow Rate: 30%
Space Between Passes: 0.2mm
Ironing Speed: 100mm/s

Assembly

Layer Order is the following

Moon
Sky
House
Tree
Owl
Tombstone
Pumpkin BG
Pumpkin
Coffin Cap