I would first try Rob at the above linked coherentsourceservice.com, if that doesn't work I would consider having the tweeter repaired by Bill LeGall at:
Millersound Speaker Refoaming, Speaker Reconing and Repair Services
Bill is well respected and considered a master of driver repairs. If you go this route you might want to send both tweeters, so that they can be matched.
With Thiel loudspeakers I would caution against using off the shelf replacements. For the earlier Thiel models while the drivers might appear to be off the shelf drivers, they were in fact custom made to JIm Thiel's specifications. Furthermore, these customized drivers were used with specific cross-overs that adjusted for these particular drivers to create a time and phase coherence loudspeaker system that was somewhat unique in the industry. Only a handful of others were willing to attempt such a feat.
Later Thiel models used in house built drivers, but the same cross-over considerations took place.
As a side note; damaged tweeters are often the result of amplifier clipping. The Thiel CS 5's were a notoriously difficult speaker for amplifiers to drive. If you don't have the proper amplification, it's quite likely this could be become a reoccurring issue.
Millersound Speaker Refoaming, Speaker Reconing and Repair Services
Bill is well respected and considered a master of driver repairs. If you go this route you might want to send both tweeters, so that they can be matched.
With Thiel loudspeakers I would caution against using off the shelf replacements. For the earlier Thiel models while the drivers might appear to be off the shelf drivers, they were in fact custom made to JIm Thiel's specifications. Furthermore, these customized drivers were used with specific cross-overs that adjusted for these particular drivers to create a time and phase coherence loudspeaker system that was somewhat unique in the industry. Only a handful of others were willing to attempt such a feat.
Later Thiel models used in house built drivers, but the same cross-over considerations took place.
As a side note; damaged tweeters are often the result of amplifier clipping. The Thiel CS 5's were a notoriously difficult speaker for amplifiers to drive. If you don't have the proper amplification, it's quite likely this could be become a reoccurring issue.