I have become a convert to the ‘2 as 1’method with anything fitted as it helps eliminate see though seams. I touched on that briefly here http://fiveandcounting-motherof5.blogspot.com.au/2011/08/silky-seashore-success.html and I made this dress completely that way http://www.flickr.com/photos/motherof5/6194582005/in/set-72157625766393530 and the inside here http://www.flickr.com/photos/motherof5/6195101670/in/set-72157625766393530/ . Granted,its not as pretty on the inside but the outer dress was just right!
However,I don’t think that is the case here,I think wrong sides together would be fine.
As for lining the skirt,I did that with my Lisette Traveller dress http://www.flickr.com/photos/motherof5/6298050242/in/set-72157626639154721.
Much easier to do the Music Box. I would make an outer and lining skirt.Hem the skirt LINING(shorter then the finished skirt will be by 1/2 ”),baste the two skirts WRONG sides together at the top matching notches and side seams. Trim a little from the centre back seam of the lining and then wrap the back placket and construct as per the pattern directions.
The hem lining may need a little jiggling to get it even and it may be helpful to baste the centre back lining edge to the skirt.
I hope this is some help and that I have not completely bamboozled you?
I am flat out this week but could do a few photos for you next week if that is not too late?
Finally,for lining,I avoid synthetic whenever possible. I would self line the bodice and use a cotton or cotton rich poplin for the skirt.
Good luck and if you need clarification on any step,please ask.
PS Pre-treat your fabric,if you are going to dry clean the dress,thats fine,if you are going to gentle wash at home you must pre-wash your fabric as it will shrink. Do be aware that some of the lustre and stiffness of the silk will be lost with washing. If you desire that finish,dry cleaning is best.