After visiting the final NBTHK exhibition at Yoyogi (http://www.militaria...tion-in-yoyogi/), I dropped by Aoi Art. Mr. Tsuruta told me that he had bought some property near Yoyogi station, and that construction of the new home and shop will start soon. He made a point of it being much easier accessible than the current shop.
Smart move, me thinks, because after the NBTHK relocates, not many people will visit that part of Tokyo anymore. I also hope it will be more spacious, i.e. less cramped, than his old shop.