Ah ok, I thought meant to just remove one of the duplicate menu entries.
Yes, we would like to move to a unified preferences pane but this depends on being able to move past Tk 8.4 as a min requirement so we can use the Notebook widget. A hybrid solution would be to abstract each dialog so ti can be loaded as either a separate window on Tk 8.4 or as a tab in a Notebook widget on Tk 8.5+.