in Wayne & Christina's LOTR READER'S COMPANION, page 671. Now that it doesn't violate any protocol or copyright I can post them here:
KEMEN the Ring of Earth
ËAR the Ring of Sea
MENEL the Ring of Heaven
At least two out of these three are familiar through their usage elsewhere, namely in KEMENTARI, 'Lady of the Earth', one of the names of Yavanna the earth-mother goddess figure among the Valar, and the other in MENELTARMA, the name for the great holy mountain at the center of Numenor (and, later, the volcano in the sea in Imram and THE NOTION CLUB PAPERS).
By the way, I don't know how to insert a diaeresis into a blog post, so just in case that name of the Ring of Sea came through without one it shd be pronounced with two syllables not one: eh-ar not eer.
Thanks again to all who pointed out to me that this was, after all, in print, esp. Wayne and Christina for printing it in the first place. As I said in my response to their comment on the other post sharing the good news, their books may now be taking on that aspect of the collection as a whole: so many good things that no one can take them all in.
*and also the person, whose name I don't know, who'd posted the information to the website where Morgan had found it.