"I'm still trying to convince myself of what would be a very unpopular opinion, which is that with T207, every variation except the 3 Livingstons is simply a print flaw... including Lewis (no-emblem)"
I agree Mike and always have. When the printing flaw creates a lack of a letter or emblem i think it's a bit more significant than a faded color. At least more interesting, but in my opinion none of these should be considered part of the set.
When printing these I don't think they intended for the letter to be missing.
Here was a printing error I found in a collection a while back:
t207 dooin.jpg
Shows that they printed dark red over pink.