"I’m aware some people think the original version didn’t specify his size"
Well, he was a hobbit once, right? So a 10 meters tall Gollum makes less sense than a Gollum that has about the same size as other hobbits, give or take.
That's a retcon. There was no indication that he was a hobbit in The Hobbit (and as others have mentioned, in the original there was no physical description at all.)
This version says it’s the 1937 edition. It has the pre change story about Gollum offering the ring which Tolkien said is what he changed. But it also says he was a small slimy creature.
