As for the Dante scholars who end up here...sorry, I can't help you.
Before I go, here are pictures of the fir louvers I just finished. The second picture shows the weird cutout that was in back of the original. I have no idea if it needed to be reproduced exactly, but I went ahead and did it for fun. The difficulty was that including the cutout necessitated four different sizes of slat in each louver. Does anybody know why these louvers had the cutout? Another good reason to send me an email!
