We're the older guys, the one's your age have grown up in the "It's all about me" generation. Though there are some exceptions to that, they're just hard to find. My suggestion is volunteering at something you enjoy, a local museum, foodbank, animal shelter, hospital. You'll meet those that think of others rather than themselves and you'll already know you have something in common. Good luck.
They're around. You may be looking in the wrong places.
Most of them aren't on EP, but still around. They don't usually draw attention to themselves, which makes them harder to spot.
I don't know about all the others, but I consider myself a gentleman, and I am right here answering your question right now!
Yes. Being a gentleman is much more than that though. It's being polite, respectful (especially to women), and selfless.