So, that guy from the Tumblr blog turned out to be a stinking liar.

Over two weeks have passed and he didn't post anything on his blog since and doesn't reply to private messages.

So, is there anyone over there who owns the Japanese USUM artbook and would be willing to scan it fully?

Not that I'm being ungrateful for the stuff he posted before, but if he didn't want to get requests from people anymore, he could just say so or simply stop doing them, instead of fooling everyone into believing that he was going to scan the full thing. Liars are despicable.