Oswin/GIRD update

So the shoulders on the McCall's pattern are definitely not the same as what's pictured.  I'm considering on using Simplicity 1800 for the sleeves portion of the neckline.  I'm not decided yet, i would like to wait for it to go on sale for 99c at work but am impatient to sew this dress as soon as possible.  I didn't find an alternative on the McCall's site unfortunately.  Apparently some have had trouble with this pattern. /:  I'm not sure i can get it to look the same (or as good) as the dress that Oswin wore.  I have a wide neck, broad shoulders, and wide bra straps to hide.  I might have to do something out of character and make a muslin mock-up before i cut the red knit (not that muslin will fit the same).  Maybe i have an old pair of knit sheets that would work better.  This is going to be an experiment, no doubt.