Yeah I did that first and it worked just fine for getting it in.
What I"m doing now is copying the source from the tiddler and pasting that into the Method Draw (looks like SVG-edit would do it too) to be able to edit the image. Then I view source again and copy paste that back into the tiddler.
I was just wondering if there was a known plugin that would read that the tiddler was svg and bring up an inline editor. Then saving it would paste the code back into the tiddler. I guess it was a long shot for something so seamless. There used to be a firefox plugin called xinha or something that did that for html.