Your id does not look like it came from 2011-2013.
Well, this one doesn't. When I got a laptop since my old desktop was shot, I think I forgot about the game when I made the switch, so I was and still cannot recover my old key. I had to make a new account on Steam for it. My old BLID was 29346, under the name, "BB Master Chief", which stands for "Boss Battles Master Chief", showing pretty much my dedication to this game. This server is what I spent most of my BL time on back then.
Edit: The main reason why I am unable to recover it is because I didn't know how to recover it at the time, and now it's too late since I don't remember what e-mail I used under that account.