Thank you for sharing in my joy!
Claire, give yourself some credit. This is the second time I've successfully altered my clothes, if you count hemming my jeans as the first. Doing the sewing by hand instead of by machine was a big help because I had complete control of every stitch.
Kappy, thanks for sharing your dart pinning method. I did try pinching out a dart but I feel like the top is already stretching too much over the chest and the bust area would become very fitted and not have enough ease. It might not work well with the bust-waist area which is loose and blouse-y and can't be fixed without raising the waist.
I was pleasantly surprised with the quality of fabric when I was doing my alterations. It turns out the fabric is a plain weave with black warp threads and white weft threads (or vice versa) so it reads as grey. Some of the sewing on the garment is well done, while in other sections it is pretty ragged (dangling threads, crooked seams).
Also, now that I'm a little more "expert", I can see all the ways the fit on the dress isn't perfect, but it's not worth tweaking it further. I'd rather buy a higher quality replacement dress or sew my own someday. This experience has only reinforced my desire for well sewn, well fitted sturdy clothes made of beautiful fabric. Now, where's my winning lottery ticket?