It's funny that a collector would give a premium to a T205 with borders tarnished to green. That's on the order of thinking a T206 should get a premium because the stock has a discolorizing fungus or the printing has faded. But we're talking Pre-War baseball card collectors here, so allowances are made
At the weekend card show in Seattle some of us (including some who were avid T206 collectors!) were joking about how things that would be considered a major defect on any other issue (factory miscut, wet sheet ink residue, bad color registration) gives a premium to T206s.