Based on other people's descriptions of the fazors, I have them. I also have a 271 serial number.
I have been stretching the headband since I got them but even more so over the last two days. I can see now that the clamping force on these is extreme. Previously when I would put them down on the table it would compress the pads together to the point where it created a suction between them that would make a pop sound when I separated them. Now when I put them down the pads are just touching. They don't touch the ears as much anymore but I do still have to keep stretching it all the time. Maybe it needs a few more days of this.
Wow! Your cans sound really tight!
FWIW, I just tried placing my LCD-3s on my desk, front-facing up and the back halves don't even touch. Never stretched them, they just came out of the box that way and I found it comfortable so I never messed with it.
I'm also 2-3 clicks from max length on the standard yoke rods.