How do I install Nautilus-Elementary?

Solution 1:

From examining the ppa itself 1:2.32.0-0ubuntu5~ppa140 looks to be the right version.

Did you try apt-cache policy nautilus to see if the ppa is correctly listed in package sources ?

Adding the PPA only lists the source as a place to get packages

$ sudo apt-get update && sudo apt-get install nautilus-elementary

is what you need to actually install the package nautilus-elementary.

While I can't say much about the author's choice in naming a package fork, it appears as if his intention is for you to add his PPA and upgrade.

sudo add-apt-repository ppa:am-monkeyd/nautilus-elementary-ppa
sudo apt-get update && sudo apt-get upgrade

I'm guessing that this choice by "ammonkey" will lead to upgrade wars with the standard Ubuntu nautilus package at some point.