Monster Zero x SciFi Japan - Archive Only

...am I right? There are only 2 Godzilla Film versions missing on home (digital) media, "Godzilla 1985" and "King Kong vs. Godzilla", the Japanese version?

Those two aren't available on North American DVD or BRD, no.

Add to that the Titra/Titan dubs for Godzilla vs. The Sea Monster, Son of Godzilla and Godzilla vs. The Smog Monster; the international dub for Godzilla 2000; along with any versions of Godzilla: Planet of the Monsters, Godzilla: City on the Edge of Battle, and Godzilla: The Planet Eater.

Then if you really want to get technical, nearly all of the Godzilla movies have different cuts with different title cards and credit sequences in different languages. Not all of them are available on home media in North America. There are fans who keep track of all of those alternate cuts very thoroughly.

Over the years, fan reconstructions of those other versions have become good enough that I don't even care anymore whether or not they're ever released on home video. I have high quality versions of G85, and the Titra/Titan dubs and a decent enough version of KKvsG.
I'd absolutely buy them if I could, but am satisfied with what I have, also.