Here is the banded kirtle (or so I've decided to call it) so far. As was pointed out, the front should dip down a little bit to more closely match at least the air filter hat picture, and probably also the Descent from the Cross gown as well, though that one is at an odd angle so it's harder to tell. I went with a square neck for this as that will work better under the gown this will eventually go under, and it also seemed a little easier to focus on one point of wierdness at a time (in this case the banding and the sleeve thing). The next iteration of this gown will have the dipped/sweetheart neck, now that I think I have the banding figured out.
You can see on the front that the line from the facing and strap is extending right into the underarm, giving the effect of a raglan seam. The sleeve is a normal sleeve shape, the trick to the raglan line is lining up the strap with the top facing bit and the armscye just right. To make that work the front neckline has to be high enough but as it turns out once the girls are lifted up and well-supported the neckline will end up in the right place.
The back did not line up with the top facing quite as well - I need to shift it down to get it to line up right but by the time I realized it was not right fixing it would have been far more trouble than I can go through without extra fabric to re-cut anything if I need to. I think if I think more about how I put the sleeve and facings and shoulder bands together I could avoid this issue next time, but again you can see where the raglan line is coming from. It's just the shoulder strap.
Overall, I'm pretty happy with how this has come out. I still need to do the eyelets down the front and fingerloop a lacing cord, then once I can lace the whole thing up I can level the hem and finish it up. The strap thing was fairly easy to work out and fit on myself, though it would have been easier to do some of the tweaking in back with an extra set of hands (duh). One nice thing about this particular design is that you can get a really wide neck and still have useful and secure shoulder straps. Even with the sleeves in and the skirt on, nothing is shifting around or slipping off and I still have a nice wide, open neckline, which will be nice with later houppelands and early Burgundian styles.