Nice, Marc - great eyes and attention to detail!
There are at least a couple other such unreported variations within T207 that don't get much attention. Some have report hat color variations with a couple of the Chi-Nat players, if I recall. A fairly clear one is found on Graney - the C on his shirt is either brown or grey-ish (like the color difference between the Big and Small 'C' variations of Livingston). Quick look around showed a number of each in just a few looks, so both seemed to be pretty common.
A more subtle I came across recently that is similar is a striking color difference on Cunningham (Wash). In everyone I'd ever seen, across all four possible backs, the blue is the light blue seen in most of the set where used for uniform content. This one had the same blue as seen in Saier's hat and emblem, not the washed-out blue like W. Miller.
Comparison images of both are below. The Cunningham images are scans from the same scanner over a number of years. In hand the color difference is very clear.
Like other sets of the times, there are more and more tiny variations once you really start looking closely. 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)
. But since I've not handled that card, I really can't judge, so for unpopularity, I'll just stick to T213-1 Coupon being part of T206
--
Mike