Thanks Soire. Good instructions on repairing Sony covers. Will give this a try.
In terms of new-in-box Sony covers, also found two on Amazon. The first is a red cover for the PRS-T2. Second is the same brown cover for the PRS-600. If you come across any others, I'd definitely be interested:
https://a.co/d/3v9bDyv
https://a.co/d/2sgaK6G