Sorry if I am coming across as a lawyer here, but the seller says the problem is where the fretboard meets the neck, and the pictures in the link are all having to do with the binding on the neck. Since he seems to be going out of his way to be very open with the problem, my assumption was that he was pointing towards the neck binding. While he did state that a neck reset had been done (isn't it a little bit early for a neck reset already, but that is very dependent on the actual age of the guitar, and the string gauge used, I suppose), he did say the problem was at the fretboard/neck, not soundboard (top) and fretboard or neck. Being as specific as he is about the problem, if there were cracks or finish defects, I would have thought that he would have noted them.
On the other hand, getting as many detailed pictures as possible is a good idea if you are thinking of spending that kind of cash on a sight unseen guitar.
I would discount the "best guitar I have ever heard" statement as being essentially worthless. We don't know what other guitars he has been listening to (was it mid 1970s Japanese made all laminate guitars, or was it excellent examples of pre-war Martins, handbuilts, and small factory production guitars (Santa Cruz, Collings, etc.)), or what his idea of a "great sounding: guitar is, as that is very much a matter of opinion and hearing variation.
Kostas