I decided to approach the issue with the method of handling svn externals (using git-svn) mentioned here - http://stackoverflow.com/a/350982/520929
The process works pretty well overall, but I wanted to handle it within magit, so I threw together some elisp (definitely somewhat raw) to allow me to fetch the SVN externals from the main git-svn repo, code here: https://gist.github.com/4471403 I couldn't really find anything on it to begin with - so maybe this will help others. Is this something that would be suitable for a pull request on github? Thanks!
