[edhans]

I looked at each of my 99 E90-1s (93 diff, 6 dupes). Found only two with the shading, both Fromme. The shading is not identical on the cards. The other Cincinnati players (Mitchell, Bescher, and 2 Siegle's) do not have the shading. I'm inclined to agree with the majority that it's not a variation, just a dirty or worn plate. As Scott points out though, if we could establish definitive patterns it might help to solve the elusive mystery of e90-1s series.