I hate it when that happens. I sold my first TG which had this problem.
When it got re-released with re-lume, I purchase it again, and within a month the same thing happened.
Texski use to fix these up by putting in gen crown stem, and tube. He'll drill into the ceramic case to fit the tube etc and fix the entire problem. Cost was not overbudget since it's only crown/tube/stem. A real patient guy when it comes to IWC. Don't see him around much now on the forums.
IMO this is the only way to go.
I've since lost the TG in stupid postage theft else I'll snap a pick. The TG was just not destined for me.