We'll need to sync up on the format/location of this file in the tarball.  Mine doesn't have timestamp (which I think is a good idea) or nodes (which might be useful, but we should chat about it).  Also, my hash has a nested hash where I supply versions for individual commands (rather than a generic top-level version number).  This would potentially allow an import to use version 2 of "replace catalog" and version 1 of "store report" (when I add support for reports).