I’m pleased to find that Phil Dragash’s marvellous full-cast/full-symphonic unabridged version of The Lord of The Rings was uploaded to Archive.org in Summer 2020, in its final 2013-14 version…
* The Fellowship of the Ring. Note that the chapter “A Journey in the Dark” has a small encoding skip, also present on other online versions, which cuts a few minutes relating to the initial search for the doors of Moria and the unpacking and warding of Bill-the-pony. Also, “13. Lothlorian” and “21. The Great River” are 2013 versions, and I prefer the originals which are in the Limetorrents version.
* The Return of the King (and one of the Appendices, “Durins’s Folk”).
To legally download this you have to own the three books, the extended-cut three-DVD movie of The Lord of the Rings, and the official soundtrack album for the cinema version. To hear the full Appendices in audiobook form, you’ll want the official unabridged audiobook reading. This is commercial, and will also give you the small missing section from Phil Dragash’s Fellowship.
There’s a Digital Art Live magazine interview with Phil here, as he’s also a digital artist… as well as possibly the world’s best vocal mimic since Mike Yarwood.