Ernie: I don't know about the cars being "equal" in milage. I would say that a 10 thousand+ milage difference would normally make a big difference in ANY car sale, let alone a Cobra. Heck, in THESE cars that could be a number of YEARS worth of driving to some of us!
I do agree that these are both fine examples of ERA's and it will be interesting to see what they go for (with the 428's vs 427's). Of course, you don't see too many "poor" examples of ERA's out there. The one's I've seen left me with a big smile on my face.