mystic vault
so, this base-building piece here is the closest thing i could find in the menu to fill the spot shown in the second picture, but as is plainly obvious, it doesn't look too good... I kind of feel like the piece that'd fit in there cleanly should be added to the game. i'd rather not have to remove the piece that's directly below it in Pic 2 that would make it fit somewhat okay.
if the piece i'm looking for does exist, please show me where in the menu it is.
celest pelican
If there isn't one, you might submit a bug report in the forums and if they consider it's needed, they might add it in the future.