The program needs to search double entries
You may need an extra program after running lee's when you do a ssget it retrieves in database order, so theoretically you should be able to find the older and new entries using a starting number. Find total number 1st and renumber backwards adding to the number the difference.

Disclaimer in database order has worked 99% of the time for me. If you add some more middle then some on end then do update it will not work.