This is a sketch I've been working on today, I tried to aim for like a "What if... Modernized Showa Godzilla", so I mainly used the '55 suit as reference for this one, mixed it with some Komodo dragon, Monitor, Crocodile, T-Rex, various reptiles and even some amphibians.
Since it's still a W.I.P. the detail/shading and some lines/ligaments may look wonky. (Still working out the design).
I made him thinner and lean since the Showa Series never really had him fat, plus most reptiles tend to stay pretty lean their entire lives. He has the fangs of 55, mixed with the head/neck of a Komodo dragon and a Croc, his legs were designed with agility in mind, that way he could pounce around quickly to dodge attacks, his fingers are also elongated and webbed. The feet I thought should be similar in size to GMK since GMK really stomped his enemies flat. The biggest difference, the tail, is a combo of things, mainly working as a sailfin. Similar to how Shin has a unique "gimmick" with his tail.
He looks a bit anthropomorphic because Showa G was always the more anthropomorphic type, but there may be some changes here and there.
P.S. that'll be a 250 foot building to the left of him lol.
He'd probably sound something like this [1:23] https://youtu.be/95lFOx-Pcgs?t=83