I got my first pair from yoox today, so I figured I should share some photos. According to the tag on the box they're "Derby Corr- bufalo". I'm not sure if that's in re: to the type of leather or just a model of shoe, but I noticed a couple of the LVR boots were also listed as buffalo. It's probably difficult to see from the photos, but the toe and heel sections are a sturdier, less aged leather. The middle section is incredibly soft- almost pre-broken in. The bottom of the shoe has a thin layer of rubber. That was a pleasant surprise as I usually end up having to pay to have some sort of sole saver put on. Anyway, I'm very pleased with them. A little bit of polish and the slight scuffs on the toe should be good as new.
As far as the size goes, these are a 41.5 which is the same as a pair of guccis I got last summer. I'm usually a 9.5 in US shoes, so I guess the 41 will fit you J-Shock. I'm an 8.5 (which I assume is the UK size) in Miu Miu/Prada. Hopefully that'll help other estimate their sizes since I assume most of us will be getting them online.