I have been working on the GUI editor script, cleaning it up and rearranging a few things. It should be much easier to add GUI controls to the collection now - adding them into the array of controls and then adding a case: for it in the onRequestNewObject() function.
You will probably want to extract the guiedit.zip archive into graalfolder\levels3d\gui to get the editor images.
You will also want to make sure that you have the TextEditor weapon added to yourself if you want to see the generated script. You can find the TextEditor
here.
I will be working on this some more.