The Kodomo no Zidaikan museum is in Niigata and it is a public place. There was a large earthquake a few years that closed the museum for a while. After this if I remember right Yuji's collection of monster toys was taken out and replaced with other vintage toys, all this being after the museum was repaired. So I dont think there is any vinyl to look at now or maybe not very much. I always wanted to go but its so far from Tokyo and expensive to get there, its north from here and on the other side of Japan.
When I went to Japan in 2007 I was planning on visiting this museum but the earthquake hit one month before and not even the roads were fixed up yet. Here is a link to the museum's website: http://www.zidaikan.com/ and here is a YouTube video that is amazing (and with a great soundtrack): http://www.youtube.com/watch?v=lKI7J3F-a0M