In the photo above you see the same sleeve! Can you imagine? I added a sleeve head and all the wrinkling was gone. I must say that, even though I know that it is a game-changer, I wondered whether it would be enough or that I would have to re-do the upper part of the sleeve. Not necessary.
I used the method described by Ann Rowley. The link shows her Flickr album where she explains the method.
Thank you for your comments. They are very much appreciated, though I do understand that there is no time to comment every time (Dorothé). When I was last active on this blog about two/three years ago I already experienced problems with replying to comments. That has not changed. Even though I'm logged in, I can often only comment anonymously. So I'm sorry I'm not replying, I keep trying!