Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
Mark, the SBD-5 is the one I fly and the gunsight isn't a tube, but actually a rectangle that sits directly in the center of the fwd view similar to a HUD, so that solid black is quite prominent. I have never found any way to activate the gunsight so correcting the alpha on that texture has had no effect. No switch that I can find (there are quite a few that aren't animated in FSX).Falcon, I had a look in the texture folder and found a file called gunsite_hellcat.bmp . It's a dxtbmp format and it's alpha layered, but it looks OK to me. But if a solid color with transparency is also in the tube I fear that nothing could be done, as you said, except find a material editor for FS9 which could alter the solid color definitions in the mdl file.
Is there a gunsight switch that toggles the gunsight on and off? Maybe it switches between the solid color and the gunsight texture, then at least the tube would be transparent when you switch the gunsight on.
Mark