Show a tooltip as well for the toolbar items (see !330 (comment 63980) for more details)
write the filename instead of the file-count if the operation was about a single file.
add the file count/name to the notify message (See thunar_notify_undo_or_redo)
Ask for confirmation if the operation to undo/redo took longer (more than 5 seconds ?) .. this requires to call thunar_job_operation_set_end_timestamp for each operation, not only for trash
Add operation-type to the menu-item label. E.g. Undo Copy (see as well #938 (closed))