Finally, with a help of a very good and close friend (who is the previous owner of the Thiel CS 2.7), we managed to replace the previous pair of coaxial drivers with the newer pair of coaxial drivers from Rob, Coherent Source.
I'm glad to hear it went well. I have the 2.7s and a spare coax/bass/passive driver "just in case" that I purchased from Rob years ago.
But I'm curious: Did you replace the coax because there was a problem with the old one? Or is there some sort of "new" version of the coax drivers for the 2.7s?