It's probably time to give up. I tried to tweak tailor to make it able to convert my repositories to Subversion for several times, but without any success. It also fails to convert it to Bazaar-NG or Git. Those are list of all VCS I consider to use in future.
I'd prefer to switch to subversion, because it is widely used and most people will be willing to use it, but I have not find any way to convert current VCS data to it. Maybe I will start with empty repository and forget the history.