They were American pressed, not Japanese. Any serious record store had at least some of them, and could order any of them .
The big box is what was Japanese. The Japanese reissued of the 12" LPs didn't come along until the 1980s or so. Verve as a non-reissuance label had petered out by then, but in the early 70s, their Bird catalogue was available.
Many iterations over the years, and still cheap:
https://www.discogs.com/label/582254-The-Genius-Of-Charlie-Parker