Gibson Custom Shop stopped doing fretless wonder frets orders around 2007. They used banjo fret wire and filed it down. I'm guessing the crown height would be 1/32" (.03125") or 1/64" (.015625"). I have heard that it was between .015" to .020". I have also heard .024". Hope that helps.
I personally like fretless wonder frets and I never had problems doing bends and vibrato on them (though you do have to adjust you technique with them). I have also like using 7 1/4" radius necks on Fenders but that is another issue.