Looks pretty cool. Thomas Preik does not have sapphire casebacks for the supercased watches (eg. GMT-C). I am curious if this one would work.
I have installed a few sapphire casebacks (story at
http://www.minus4plus6.com/caseback.htm) and if I had to send my watch in, I would just spin off the sapphire one and replace with the original.
Thanks for posting and looking forward to hearing more about the details of this particular caseback.
-Sheldon