My first muslin

This week-end I started working on this dress from BWOF April 2008:

After reading through the instructions, I realized this one was a bit more complicated than what I've done before, in terms of construction. I actually have high expectations for this dress, so I wanted to be sure the end result would be up to my hopes.
So friday morning, after attempting a quick tissue-pattern fitting on my dress-form, I decided to make a muslin. Thankfully Gala Fabric is only a few blocks from my house and I was able to pick-up some stretchy nylon (my actual fabric is a stretchy cotton and is a bit heavier, but for $2/m this will do...).

So in a few hours between Friday and Saturday I was able to put it together. I actually went through the trouble of making the pockets. I probably could have just stitched the pocket yoke to the skirt, but I found it a good opportunity to practice, as they were in fact a bit more intricate than I first thought.

I didn't sew any of the facing so the collar doesn't stand as well as it would ultimately, and I omitted the zippers though I might have to put the side one if I want to be able to easily try it on myself. This is also a good opportunity to test my dressform's accuracy.

So now I have to figure out how to alter the pattern to get rid of a few little fit issues...

As usual with Burda patterns, even though I picked the size that matched my measurements for bothe bust and waist, the dress is too wide. Maybe that's meant to be the ease, but this design is supposed to be close-fitting so I don't know...
In this case, I might actually downgrade the waistband and skirt to a 34 (it's a 36 right now), but I'll keep the top a 36 so it doesn't get shorter.

The bodice has a few little problems. For one thing, I think the bust darts come up to high. In Fit for Real People, they say darts usually need to end at least 1" from the apex. In this case, it seems like the design has them finish right on the apex (but I am assuming that from the photos, since Burda patterns, unlike others, don't actually have any markings for the apex on them). I think on my dress form they go a bit higher though...

You might have noticed that the right side is actually smoother than the left. I'm not sure why, I will need to try it on myself to see if it's a construction problem on my part or an accuracy problem on the form. However on both sides there are wrinkles that seem to indicate I have square shoulders. Again according to Fit for Real People this can be fixed easily by raising the seam at the shoulder (while it stays the same at the neck)...

The neck gaps a bit at the back, so I might need to do an horizontal tuck there.

But here is my biggest issue. After pinning about 3/4 of an inch on each side for a tighter fit, this is what the back looks like:

Hello sway back ! Now I'm not sure if I should add darts, and how long to make them, or if I should make an horizontal tuck or raise the waistline seam...Anyone outthere has any suggestion, let me know !

And now this is just a photo of the muslin on the right side, so you get a better idea of the shape whithout the confusing pocket mess ...though the fabric print is quite confusing in itself, you can barely see the pockets even though I obviously didn't bother matching anything...It's quit a good exemple of fabric style not being right for a garment design, as all the interesting details just disappear in the busy print...

So this is where I am right now, not too sure what my next move should be.
I am actually starting a new job tomorrow which will most likely involve long-hour days plus my summer week-end are starting to fill up rather fast, but hopefully I can still find some time in the next few feeks to make the alterations and complete my dress. In the meantime, if anybody out there has suggestions or tips, or thinks I am mistaking on some of the fit issues, I'll be very grateful to have your opinion !