Migrate source code with history between v6.0.2 servers

I have a requirement to migrate projects with several years of source code history from one RTC v6.0.2 server to another; there is no need to migrate work items or work item history.

I'm aware of possible options including enabling cross domain communication and establishing friend relationships, but I'm not certain either of those options would help in this situation.  Last, I've considered saving significant baselines from each project off to a file system and manual re-building that history on the target server environment, but that doesn't sound like a great option either given the requirement is to migrate all file history.

Any other thoughts or best practices anyone can offer?

Thanks in advance.