Matt,
I agree with jags...these
look good and come from a reliable source. One concern I usually have about used tires is how they were stored. Schwalbe are encouraging there as well:
http://www.schwalbetires.com/tech_info/tire_wear SCHWALBE tires can be stored for up to 5 years without problem, but to attain this they should be stored in a cool, dry, and, most importantly, dark place. When stored properly, even longer storage times may be possible. If fitted on a rim, tires should always be inflated or the wheel hung up for storage. A bicycle left on flat tires for an extended period may damage the tires' sidewalls.
I have a pair of Marathon Plus tires I plan to put up on eBay myself. They have gone a total of 1km (tire-mudguard issues on the 700C bike they were fitted to) and the center mold-mark looks about the same as the ones in the SJSC photo.
Best of luck, Matt; these look like good ones!
Dan.
