Insert sigh of relief here! I found my copy of Tessa Lorant's long out-of-print Knitted Lace Edgings today. Mine's a second edition, circa 1982, which is about how long I've had it! I've got two of her other books, but the edgings are the most useful.
After much swatching, I've decided on the next shawl, which may go to IK, if they ever update their submission guidelines. They take swatches, sketches and hot air rather than finished stuff, but I prefer to work out the whole design first. Whatever ...