I have the duct material you sent, you know, the paper towel roll :) Anyway, the O.D. is definitely 2 1/8 so you'll want to change the drawing dimensions. Not a big deal, I just figured others have had to deal with it and wanted to know what worked. I haven't veneered, or painted, or leathered (?) the baffle yet. I think I'll prolly let gravity hold the tube in some glue as Matts wrote, adding the thickness of the baffle to the port length. Thanks Matts.