I don't know that I've ever worked in such a state:
See the wine on the floor?
OK, I actually think I might be getting somewhere but my fix is SO BIZARRE I wouldn't believe it if I hadn't come to it with trial and error pinning. Note: I'm about to make muslin 8 (I think it's 8). I've actually started tracing the pattern pieces because I'm afraid of the cuts I'm making now.
Here's the sleeve in its original form:
There's slightly less curve on the right side (the front sleeve) than on the left (the back sleeve).
However, given the changes I've needed to make to the side front piece - and to get things to fall smoothly in light of a) where the side front meets the front at the armscye and b) the topography of my chest leave me with a sleeve that looks like this:
Again, the right side of the photo is the front sleeve. From the sleeve head to the left (the back sleeve) there are no alterations from the original pattern.
I've pinned this and it works. Is this even possible???