"Are there any "old-earthers" (as opposed to young-earth literal creationists) who also hold to a literal Adam & Eve, created ex nihilo?"
Virtually all old-earther literal creationists hold to a literal Adam & Eve, created ex nihilo. Those who don't are technically not OECs, but probably thiestic evolutionists.
"Who was Adam?" recounts the scientific evidence against evolution, arguing for the special creation (from scientific evidence) of all hominids and humans. I'm not sure where you found "theistic evolution" in that.
Much of the confusion comes from YECs who like to equate OECs with thiestic evolutionists. There are some major, obvious differences between them.
I was confused on that exact point myself, and it appeared others might have been as well. I greatly appreciate your answer and clarification.