Greasy Fork is available in English.
Creates the option next to edited and deleted Reddit comments/posts to show the original comment from before it was edited
< Unedit and Undelete for Redditについてのフィードバック
I works fine for me in both Firefox and Chrome. I'm using the Violentmonkey add-on.
Attempting to install using Greasemonkey fails with an error about an invalid match domain. Manually fixing that match domain in my own userscript copy still led to no visible change in reddit's UI while using Firefox. Staying on Firefox, tampermonkey doesn't prevent you from installing the script, and it shows the "Show original" button on loading reddit, but then the show original button disappears within a second or so. I tried disabling RES and my adblocker, and a few other extensions, but still saw the same behavior.
On Chrome, this script seems to work as expected so far with Tampermonkey.
Thank you for this userscript!