Another older guy here too - getting AARP ads in the mail (like, mail made out of paper!), and my T-day is late in the last millennium. So doubly ancient! I think there are not a lot of spaces for longterm transitioned guys ("transitioned" including social transitioning, and not solely medical), and also not a lot of spaces for older guys starting their transitions. For me, I'm not out on sites like facebook, even though it's a way to keep up with the guys who were my "littermates" or who I knew from the very early AOL lists or the Gazebo.
One thing I have started to do over the last 4-5 years, is to make an annual "date" with some other guys whom I've known a long time. We meet at a conference (the Philadelphia Trans Health conference, which is free to attend), and share rooms, and eat really cheap - except whoever has the best-paying job that year buys drinks one night out at a restaurant. These are guys I'm growing old with, who I might not speak to for months or even a few years, but when we get together, it's just...comfortable.
I guess I picked a good night to check out this site!