Question

I know how to create an svn branch w/git. But, can I do that off of a past revision/commit ?

Answer 1

Answer for myself (and anyone else) – not strictly git-svn, but it works:

svn copy https://foo.com/svn/bar/trunk/@6635 https://foo.com/svn/bar/branches/mybranch -m 'creating a branch'
# in your git working directory
git svn fetch
git branch -a

You should see remotes/mybranch in that list, now create a local branch that tracks that remote

git checkout -b local_mybranch remotes/mybranch