Great pictures, David!
I wish we could have more than one cat at a time. We've shared our home with three, over the years. And, every one of them has been an "only child".
The first two definitely did not like other cats around. Louie, our current boy, we don't know for sure.
But, he can be very ornery when he wants to be. And, at 15 pounds, down from 18 when we first got him, he could definitely do some damage if he wanted to. He's never been fat. Even at 18 pounds, he was all muscle!
We adopted him three or so years ago, as a stray who was hanging around my in-laws' yard. He was trapped, with the intent of doing a neuter and return. But, we were asked if we would mind taking him in while he recuperated, and he never ended up going back. He's a strictly indoor kitty now. Well, except for the few times that he's scooted out. Fortunately, he didn't go too far, and I was able to scoop him up every time.
Sometimes, we wonder if he'd like another cat to play with. He has a ton of energy! But, we don't want to bring home a cat, give our hearts to him or her, and then have to get rid of them because Louie won't accept them.