Hide & Drink, leather thimble — Fits perfectly. I can even type with it after sliding down it over my first knuckle. When new, it's juuussssst a bit tight, which means that when it loosens up as it ages, it should still fit pretty good.
Clover leather thimble (レザー 指ぬき), size large (part number 56-815)[2][3] — It's very similar to the Hide & Drink thimble, with some important differences — The seam (the one in the anterior/posterior direction) has noticeably less bulk, the diameter is just slightly larger (which is perfect for me), and the leather feels softer. This is my favorite.
Clover Mfg Ct, Ltd in Japan[2][3] is a decent-sized company with a long history, so hopefully its products will be available for a long time.