Good for you guys, you are holding your weight. You are a little heavier than college, but you're keeping it under control and not allowing a death spiral to happen. I want to elaborate on that part of your post, which is probably not the part people focus on.
I'm over 50. I've had some of these thoughts ('the slow metabolism!'), but we need to be careful to compare apples with apples.
To start: some haven't finished maturing physically by the time they start college. The maturation process has a metabolic cost. Some began college as a scrawny freshman and ended as a trim but well-muscled senior -- meaning a gain a potentially a few pounds during college prior to the recalled 'college weight'. In such cases, that massive diet in college was actually resulting in gains.
In the intervening years, there is usually a habit of gaining weight: in this case, 15 lb since college. That's worth about 100 cal per week, or a mile per week. Not a lot, but not nothing. The point is that adaptation can happen to being on a gaining trajectory. That becomes the norm (gaining was the norm since infancy). It's a change (struggle?) just to break even, and when you need to lose, the change is more severe.
You are probably more sedentary than in college (during non-running times), as a general rule. In college you might have walked everywhere, played pick-up football or basketball or hockey daily, danced, bicycled, paddled, whatever. How often do you do that now?
When in college you could go hard for a long time, and then get up and do it all over again the next day -- even if you hadn't slept particularly well. The intensity of exercise was almost certainly higher: you can't do that now because you won't recover, or you might hurt yourself. Or looking at it the other way around: in college you had much less down time from injuries. That translates into both more calories burned from exercise, but also more tissue-repair cost, metabolically speaking.
Beyond that, the more time you are active, the less time you have to be eating and snacking. And the more you are in a rush to get someplace (think of the college life), the less you are going to linger at the table enjoying your wife's good cooking (as opposed to some plastic mac and cheese).
I would also say that most college kids don't have stretched stomachs, but we stretch them a little over time and tend to raise our eat-until-full sense accordingly. And that's not even addressing the increased portion sizes that are now generally sold, which make apples-to-apples comparisons pretty hard.
Body composition will have something to do with it. So will some other things. Some of these you can classify as metabolism, but there are many other factors that play into it.
These things are not all applicable in all cases, but I am pretty sure most of them are in many cases. I don't want people to despair about being over 40 and having a slow metabolism; I want them to understand that there are many common sense explanations about why it is harder to maintain the weight, and that once allowances are made for those things, the metabolism issue isn't a huge one and can easily be overcome.