I've given up for now on changing the icon for Personal Launcher in the status bar. The changes persist in the panel selector screen, but not on the actual status bar itself. Somehow I did get the icon to change, but now it looks like a drop down menu with a Windows logo on it. I have no idea where that icon came from, but it's better than before.

Now I just need to read up on editing themes. I think the answer may lie in there.