Definitely intend to minimize compression so 1080p BD50 is the goal.
As for the The Fort scene, I'm using the MGM BD's English DTS-MA track as the source, which I converted to a mono 2.0 track using only the front left, right and center channels. There is sound information in the L and R (e.g. the confederate soldier greeting AE, "Welcome, my friend!") that is not included in the center channel so that's why I used all 3 channels. The next step will be to adjust the volume/gain to match the LD PCM audio.
I'm in complete agreement with you about the voice actor sounding better than aged CE and EW. If The Fort scene sounded as crappy as the other "bonus" scenes I wouldn't have included it.
I'm looking forward to all the new releases next week, as well as the German release of GBU in 2014.