As we know, at TBC launch, the vanilla honor system was revamped and replaced with the one where honor points are used directly as currency to buy PvP gear. But, those who had achieved a PvP rank were able to keep their rank as a selectable player title, which served a purpose of aesthetics/bragging rights only. On Feenix and other TBC private servers, there is never a single player around with a vanilla PvP title, for obvious reasons, and it was always a bit immersion breaking. The rumor is that it will be possible to copy or transfer characters from the Vanilla realm to the planned TBC server.
So, my suggestion is to give copied/transferred characters their PvP rank at the time of transferring as a selectable aesthetic-only title, similar to what was done on retail. Possibly with a restriction that only one player per side can have the R14 title so that there's not an entire server full of High Warlords running around.