Really, all this post is for is to tell you what you probably already know:
BE YE NOT SO DUMB
OF COURSE they were gone when I decided to go back for the others. OF COURSE.
So now my bedroom windows look like this...
What did turn out OK was my super cheap-o altering of the curtain finials. A quick sand, and 2 rounds of whitewash (and wiping off) left me with new, fresh feeling finials, at least.
Now, the search begins for 4 curtains...