A further note from Jordan Fields at Shout! Factory:

I’d completely forgotten about the MST Hour wraps for “Gamera” and “Gamera Vs. Guiron” until reading their responses to the extras. Fortunately there is still time to include, so I will. As for the KTMA host segs (or any footage from KTMA), I was not able to include.

Here’s an update Vol. XXI: “MST3K Vs. Gamera” (as it will be called). As you already know it will contain all five Gamera episodes: 302- GAMERA, 304- GAMERA VS. BARUGON, 308- GAMERA VS. GAOS, 312- GAMERA VS. GUIRON and 316- GAMERA VS. ZIGRA. It will be in a tin box. The street date is Aug. 2

The extras will be:
* So Happy Together: A Look Back at MST3K and Gamera
* Gamera Vs. The Chiodo Brothers
* Gamera Obscura: A Brief History by August Ragone (author of Eiji Tsuburaya: Master of Monsters)
* Original Japanese Trailers
* 5 limited edition mini-posters by artist Steve Vance