See the attached picture of a gen crown.
The gen crown sits closer to the bezel, while tw crown is closer to the case back.
That's why the gap is so obvious in tw sub.
Thank you for pointing out this flaw, which you can find in tw, cn, or "perfect" sub.
With this in mind, I can easily spot a rep.
I checked a pre-f Sub from my friend, there is no gap as you pointed out. I also checked the picture of your TW sub from another post. It seems that the gap is due to tube hole not being centered. Tube hole is closer to the case back.
So it's either POLEX also has QC issue or it's really a TW sub
In my collection, this sky/moon is the only one I didn't and will never wear.
This one is so ridiculous, but interesting, that it worth a spot in my watch box.
BTW, anybody knows how to change the battery on the back ?