This is fascinating!
It strikes me that Tolkien didn’t simply tweak the character of Gollum: rather, he seems to have recharacterized, at least to some extent, the ring itself.
The ring, as it is depicted in the ring trilogy, is the embodiment of spiritual corruption. A being cannot possess it without being possessed by it, and twisted by it. And, among other things, one who is twisted by it becomes consumed with a desperate desire to keep it, and will lash out at anybody who seeks to take it.
So, it seems inconceivable to me (as one who has never known the original version of the Hobbit) that Gollum would feel what seems to be genuine regret at NOT being able to give it away to one who bested him in a contest. Gollum might, disengenuously, offer the ring to a being as a trap, but he would never offer it to anybody with the intention of actually letting them have it. I suppose one could speculate that, In the original version, Gollum never intended to actually give the ring to Bilbo, but i don’t see anything in the original text that would support that inference.
Also, the ring, in the ring trilogy, twists it’s owner into a being that is malevolent, grasping, treacherous, and hateful. It would not make a being barbaric but honorable, it would corrupt the creature absolutely. Gollum, having possessed the ring for centuries, MUST be hateful, deceitful, and cruel for the ring to be what it is in the trilogy. (I suppose that since the length of time that Gollum possessed the ring isn’t specified in the Hobbit, Tolkien might have originally understood him to have had it for a much shorter period of time. But I still think that the ring, as depicted in the trilogy, would have corrupted Gollum enough to make him much more hesitant to part with it, even If he owned it for only a short time).