Re-compress svgz files with:
find . -name "*.svgz" -exec advdef -z -4 '{}' \;

That saves around 6MB in trunk without any restrictions.

Also correct the svn mimetype for all svgz files which had a wrong one (which is thy reason why my fist commit failed...) with:

svn propset svn:mime-type 'application/octet-stream'