I decided to interline the sleeves with my ticking, but not to line them because I didn't want the armscye to get overcrowded. This meant that I have to catchstitch the seam allowances and use bias tape to enclose the cuff seam.
This was a lot of tedious hand sewing, but I finally got that done over two nights.
I took one cuff off and reattached it and things were back to normal. Then I set the sleeves. Even after all the fiddling I did, I still felt that the armscye was uncomfortably tight. I was ready to "rage quit" this project, but William suggested that I leave it on the dressform to stretch out for a few days. That helped a lot. The arms aren't perfect, but I should be able to wear this for a few hours at a time now.
I marked out the buttonhole spacing and put the buttonholes in all 1/2" from the left opening. I haven't checked yet, but I'm pretty sure that the holes were supposed to go on the righthand side. Oh well! As long as the other air hostesses do the same, we will match.
I also knew that I was going to need to use the button placement to do my last fitting tweaks, so I tested the button placement using safety pins. I thought this was rather clever. (NB: the 1/2" ball buttons needed the same opening as a 5/8" flat button)
And it's done. I tacked the patch onto the left sleeve and we're good to go. More full-costume images to come in a few weeks!