Just saw this, will leave this here:
https://www.amazon.com/Ayotu-Colorfu...asis+2017+case
Someone seems to have figured out that it is a good idea to make a replica of the Amazon case, and one that apparently works well.
UPDATE:
Just received my cover. It looks slightly less high quality than the original cover (I don't like it when the color of the seam does not match the material 100%; but: no branding) but it attaches nicely (not perfectly aligned but close) and, most importantly, holds on to the Oasis when opening the case and when hanging the reader from the cover. This is realized by a non-sticky gel patch on the inside of the back flap that provides additional adhesion.
I would recommend it to anyone who is currently looking for an alternative to the unavailable Amazon cases. Shame there's no high quality tan leather option.