Interesting thread. I think Gareth got it right in saying that Mod was a state of mind, being interested in new things, fashion, films and certainly music.
In many ways the Mod scene was the blueprint for the Northern Soul scene, especially the allnighters and the obsession with records. I don't know what things were like in the north of England, from what people have written Mod appears to have lasted longer, it was over in London in 1966, but I still went out to clubs to hear soul music, but stopped doing nighters when I started going out with the girl I eventually married.
I go to the 100 Club allnighters fairly regularly, they aren't much different from those I attended back in the day at the Scene. Some of the same records are played but things have to move on. I wouldn't want to go to a night and continually hear the records I danced to back then.
My partner says she can tell I was a Mod because “you're funny about your clothes and appearance” although others may disagree.
I could say more but have now wish to bore everyone.