Most guys I know his age and even into their 50s who start over also seem to start new families. I’m not sure who @geeky_mama knows, but I find her statement very surprising. Guys love to have more kids. Especially with a younger woman—because she can keep up with the kids and he gets to do the more sedentary stuff. Although they also like kids because they keep a man young.
At best, this is probably something no one should generalize about. It’s an issue. Does he want more kids? Would he have more? Too soon to ask. But something to think about.
The age gap is not a big deal, unless you have prejudices about that as many do. But many young women like older men. They are more stable and more mature and know more about what they are doing. Young women with “daddy” issues are often attracted to older men. They are looking for security they may not have had growing up. These are not bad things.
Older men like younger women because they are younger and sexier and better equipped to have kids. Also they may be more pliable and agreeable than older women, who know their minds better and have more confidence. Older women would say older men who like younger women are immature. I say, so what? But that’s theoretical, since I’ve never been in a real life relationship with a younger woman.
If the relationship lasts, then you can pretty much count on being relatively young when he dies. Issues of being involved with his children are problematic. It is not easy being a step mother. Few step mothers are able to treat step children equally with their own children. You probably shouldn’t even try. They are his children. Sometimes they are roommates. You want mutual respect, if possible. You can’t order them around.
The psychological issues of why you would be attracted to an older man are something to investigate, too. Therapy would be a good idea. You want to develop into a mature woman on your own, and that can be hard in a relationship with a much older man. You can get set into ways of relating that aren’t healthy over time. You may find your independence of thought being corralled. He may resist changes in the power between you over the years. Those are things I have seen. They are tough, but you can deal with them.
Should you? Depends on what you get from him, and how well you think you’ll be able to work with him. Hey! Guess what? That’s the same as it is for any relationship!