No idea on the age of the tires, but they were in the factory plastic when I bought them last summer. As for the discontinuity--I love them big words like that--I'd say it goes completely from side to side with a series of smaller, shallower discontinuities along side and probably to a few millimeters in depth maybe right down to the threads. I'm getting ready to head out to my pt job now but could snap a couple of pix later and let you be the judge if you're still interested. Other than the crevasses, the tires are still supple and in nice condition.

yellowjersey does have an absolutely horrible website--according to a friend it's an accurate mirror of the shop--but you can't beat their 3 for $50 price for brand new tubbies and they are great tires, I run several sets.