1.  $6A_FIC_RU$oA FIC RUN  -- leave incorrect $6 and update $o only

2.  $6A_FIC_RUN$oA FIC RUN  -- fix both incorrect $6 and incorrect $o

3.  $oA FIC RUN  -- delete incorrect $6 and update $o

Any thoughts on which of these approaches is preferable? 1 and 3
assume that Koha will update $6 based on the new data in $o.