Managed to refactor the GUI of the app by starting a new JFrame, building the new structure, and then copying and pasting the top-level components over. In the process, multiple instances of some components were added, and could not be found for deletion, and multiple consecutively-numbered instances of their event handlers were also added. I fixed all this by editing the .form and .java files in a text editor, with the IDE shut down. Once I'd got the new GUI working as the old one did, I shifted the old into an archive package (which required me to add to its import clause the libraries from the main package on which it depends. I'll delete it as soon as I'm sure the new one is fully functional.

Next, I wrote the code to factor out the individual readings and witness sigla. This seems to be working just fine; I now have a block of <app> tags which reflect the Collate output correctly. Now all I need to do is figure out how to create a complete TEI file including this info. Then I have to save the file.

I've also added a label and text box for the base text id, which will need to be included in the output file. This can't be completely derived from the input file name, but enough of it can (e.g. LDev003) to hint at what it should be, and how to find it.