Mine's definitely one of the older models, and I bought it almost a year ago. It's not a GT, either.
Hoping not to side track this thread too far with questions and comments, but here goes...
Programming changes from the older lights to the new? I really need to follow the HDS section more, because I'm in the dark without a light on this one.
Does your light tail stand? Mine does, with only minimal wobble. It seems to wobble a bit more now, as the tail cap ballooned a wee bit.
I too thought the newer versions began in 4xxx. Also seem to remember reading a while back that the serial numbers were not sequential.
BTW, love that avatar. Have you heard the Miller Lite: Real Men of Genius commercial about the way too proud of Texas guy? And lest you take offense, know that I'm one.