Thanks for the hard work on the patch DT.
One little thing just occured to me the other day. The tube-sight in the SBD actually has a slip indicator around the bottom edge. I don't recall this being modeled in il-2. There is an image in a book, but I can't find it online, and I'll try to scan it.
Furthermore, those types of sights on these and other aircraft may not actually be "telescopic" in the sense that they provide magnification, but the pilot looks with both eyes so that with one eye he sees crosshairs projected on infinity and with the other, keeps track of the moving target. The overall effect is similar to that of the crosshairs projected on glass. If it's true, then the view through these sights should look like those of the Aldis sights in Rise of Flight.