The slip case is now finished - here it is with the book in it, showing the spine:
When I showed it made up but without the book it might have looked the wrong way round, as though the opening was on the wrong side. In fact, it's that way on purpose, so that when the book is in it the spine is on display while the embroidery forms the front.
Presented a bit more nicely on a stand:
This is the first slip case I've made for a while - I think I should do a few more!