The Daiei Region 2 DVD of Gamera Vs Gyaos(1967), which presents the film in it's original (widescreen) 2:35.1 aspect ratio, has become hard to find on the internet. The film was released by AIP in the U.S. under the title "Return Of The Giant Monsters" and has been released twice on DVD under its Americanized title:
-by Image Entertainment in June, 2004 as a full screen(1:33.1 aspect ratio), Region 1(NTSC) release and paired with Toei's 1966 fantasy-kaiju epic The Magic Serpent
-by St. Clair Entertainment in March, 2005 in full screen, all region(NTSC) as part of a nine(9) film DVD set.
To see the Image Entertainment R1 DVD release of Gamera Vs Gyaos(1967)/The Magic Serpent(1966) and the 2005 St. Clair Entertainment Group nine movie DVD set release click on the above DVD cover art images.
The original Daiei trailer for Gamera Vs Gyaos(1967):