If somebody knows where it might be still obtainable…
Mine had too many keys not working, replaced it for a 2nd one, which had non-working keys, too. Ifixit, or repair-stations won’t have it anymore, so I think I’m a little lost… maybe you have some ideas or hints? Or maybe a spare part you want to sell?
Not sure if this site is still doing business, but you can try https://buyanop1.com . I looked, seems like a lot of parts are out of stock but maybe the site’s owner / operator has an idea on what you can do. I’ve got a sticky stop key, but thankfully it still works. I’ve been on the lookout as well…