This is a backport of @StanislavGrinkov's solution to #1140 (closed) via !397 (merged) and !406 (merged).
The code is nearly identical. The only differences are one GTK3 -> GTK2 change (gtk_radiobutton_join_group () to gtk_radiobutton_set_group ()) and UI re-arrangements to match the new dialog layout backported in !821 (merged).