Yep, those are both legit!
The UK Special Edition of GOTU used to play on the Sci-Fi Channel quite a bit over here back in the late 90's, and even had a limited theatrical screening I remember. It was the only Gamera film (and version of a Gamera film) I'd seen until I bought the R1 DVD set of the complete Heisei trilogy several years later.
And as ridiculous as it may seem now, I still have a soft spot for that version of the film and really wish it'd gotten a proper retail release, instead of just as a random free disc included with some games magazine years ago (I think?).