Good explanation on the fading red Greg. Like you on a rare occasion I see an example that is possibly a mis-print/variation but I don't trust any of them enough to ever pay a premium.
Here are a few T206's that have fading.
This Beckley was tacked to something with another card tacked over top of the right hand corner
Beckley.jpg
Pickering that had some kind of frame around it
Pickering.jpg
and a Beaumont with an outline of a corner tab
Beumont Sun corner tab.jpg