32, I have found myself at loads of different sites, I would say the average player I come across is 20-35, Male and with a high enough income to justify expensive toys. There tends to be a bit of a cool down when things like kids, mortgages, wives and GF's get in the way, then it picks up again for the older guys who come with their kids. So there are two outlying groups 12-18 coming with dad, and 40-50 ie the dads.
Good on you Beethoven you would be the oldest I have come across, although age doesn't often come up in conversation, the focus tends to be on kit.
Having said that, with all hobbies there are all sorts, I have played alongside and against, the young and old codsofters, cadets (who really should have had better skills), ex forces, serving forces, retirees, students, doctors, lawyers, engineers, stockbrokers, builders, plumbers and brickies. The one thing I think I have found in common with almost all sites is there is always a tree surgeon playing!
Oh and my fitness is shocking!!!! It doesn't help that my ankles are weak from years of rugby and lots of sprains and I had an op to remove some torn cartilage in my knee after a fall at an airsoft site a few years back. I always say I will leave the running to the younger guys but somehow I always end up having to show them how to fire and manoeuvre up the field. It is one of my aims this winter is to sort out a proper exercise routine.