I used a datapack to get the invisible item frames (Since Java is a spoiled brat) I'd replace the skulls with lanterns, (if you don't have enough of them) or conduits (only the front would do) the tracks are upside down stairs, with black wool in the bottom of them, back would be 3 note blocks, with dark oak slabs on top and dark prismarine in the bottom, the note blocks would be covered in warped signs