Today as I was looking at a wall here I thought I could display skulls from the top of it. Then I realised I could/should have a skull facing both sides from the top of the wall. Double-skulls!
One cranium with a faces pointing in opposite directions!
first I'll make a sheet metal "U" shape to fit the top of my wall. I'll put a long bolt up through the middle of the "U", the "U" gets turned upside-down to ride the wall with the bolt pointing skyward to attach the foam insulation board to , puncturing the foam with the bolt, adding a big steel washer and nut to hold it there.
I'll carve the skull with a Dremel, then cover the foam with a thin coating of Bondo to make that bone-look and feel to it(I have done this before)
I still have some skulls in that room I made from rolled newspapers 23 years ago that still look good!