Hmm... I'd like proof (of the first one, not the second!). I've never seen any pictures of Dee with a fretless, and there's nothing in the sound or performance of "11/17/70" to indicate he's playing fretless there at all. Except for two songs, Dee didn't play on Elton John albums except "11/17/70" until "Honky Château" in 1972. He's not on the "Elton John" at all. He plays on "Amoreena" from "Tumbleweed Connection" (though he and Nigel sing on a few others) and on "All The Nasties" from "Madman Across The Waters". BTW, "All The Nasties" is the first recorded example of what became The Elton John Band of Dee, Nigel, and Davey Johnstone.
John