Some others that may be viable, but I haven't had an opportunity to test them:

This one probably will require modification like the one I got:
https://www.amazon.com/Fintie-GlowLight-Premium-Leather-eReader/dp/B0786XSZMR/

https://www.amazon.com/GlowLight-Universal-Premium-Kickstand-Protective/dp/B07YYTM5SF/

https://www.amazon.com/Style-Leather-Reader-Pocketbook-tolino/dp/B077GSW7YR/

Select a 6" model on this one:
https://www.amazon.com/Universal-Cover-eReader-Tolino-Ebook/dp/B07WZR7W7P/

None of these appear to have pen loops, but may be able to tuck the pen in the closing strap on the latter three or add an elastic loop to any of them.