Is there a way to merge two incremetal SVN dump files generated using svnrdump from two separate repositories, while preserving revision histories?

Question

The situation is this. An SVN server migration was under way. At some point a new SVN server was set up but some users continued to make commits to the old server and some others to the new server (yes something went wrong in the change management process). We have identified revision number X as the last revision where both repositories were identical. Is there a way to combine the commits made after revision X on both repository locations, with the understanding that the revision numbers themselves are subject to change, and then transfer them to the new repository, while preserving the commit histories?