this may make a big difference! look on one side of the louvered opening for pin/finish nail holes. you can remove the "sticking" (the trim that holds the louvers in place) on this side and pull out the louvers for sanding, etc. if you break any of the sticking, you can ususally buy some trim (window stop, etc.) to replace, and since it will most likely be on the inside, no one will know if it isn't a perfect match. oh yeah, number/letter your louvers for remove and replace.

i'll bet JerryGarcia knows a little something about this, you might ask him.