Looking closely at the side back and shoulder seams you can see that they have not been sewn together in the manner you might see 18th century garments, particularly frock coats. In these garments you see a two layers (fashion fabric and lining) sewn face to face with a piece of fashion fabric, then the seam is ironed towards the single piece of fabric. Over this seam and single piece of fabric is laid a piece of lining, the seams tucked under and then whip-stitched to the existing seam.
I'll have to do a little demo on how I think this seam is done, but essentially I have the two fashion fabric layers together in the middle, with the two lining layers on each side. You sew from side to side, only three layers sewn each time. Its very complicated to describe but easy to do.
[Edited on 24/12/2013 - I've just found an excellent demo at http://stay-ingalive.blogspot.de/2011/03/how-to-do-weird-running-whip-stitch.html ]
|This is an example I made (my blue regency dress made from a silk sari)|