Re-Scan Library but keep watched status?

After reading through another thread, I am interested in seeing how well the XBMC scrapers work as far as Movie Sets (I currently manage through Ember). My plan is to take my Rasp-Pi and scan my library, and if I like the way that things get laid out, I may want to re-do my shared MYSQL library.

Is there any way that I can have my whole library re-scanned with the XBMC scrapers (bypassing the NFO files I have in each movies subfolder) and still keep the 'Watched' status on each movie? I would hate to have to spend another couple of hours re-tagging movies as 'Watched'.

Thanks.