I've managed to get a GUI running and after lots of experimentation have it so that it displays and works almost as I desire.
The top Panel has a JList with scroll bars on the left and a JButton on the right.
1. The JButton is placed all the way to the right - I'd like to have it centered in the remaining space or just a bit to the right of the separator which is to the right of the JList.
2. The height of the pane appears to be half the height of the GUI . I'd like the height to be based on that needed for the JList.
The bottom panel is the same height as the top one and the buttons are all to the left. I would like this panel to be just the size that it needs to be for the 4 buttons.
I just don't understand the interactions and I must quite until next week.