Looks like the rotor is touching the back of the caseback? The case looks very nice, I would go for it if it wasn't for that green stuff on the dial, and I'm usually a fan of this kind of aging! Maybe at $550...
The price isn't out of the ballpark if you like that much patina on the dial, but I wouldn't go for it unless as a parts watch - and it would have to be cheaper than $600.