I think it is very possible to make good friends, but you have to try, and be proactive.
Don't think it's because you're 38 and a guy.
I slowly opened up to people I met at meetings - I am 130 days sober - and have begun to make good friends. One thing that has helped make them good friends is doing things outside of AA- yoga, dinner, sitting to talk somewhere after a meeting and enjoy getting to know each other (we already have stuff in common, so sharing that but also learning about the rest of each other).
Kinda like making friends anywhere, it is harder as an adult than it was in school or even at work. But I think people want connection, perhaps in AA even more because we are usually coming from places of solitude to some degree.
The suggestion of going to events is a good one, and recognizing others then introduce yourself....do you have a sponsor? Doing things- just a weekly meeting- can lead to meeting others he already knows.
I say hang in with it and try a few different "approaches"!