An interesting example of both post-apocalyptic and alternate-history SF - because we have two Earths, one in which World War II didn't happen, and one 300 years from now after plagues wipe out all life on our
However, it has a few really annoying problems. In the first place, the central character, Verity Auger is an archaeologist. Well, when you are going to rely on focus on a field, you'd better try to avoid anachronisms. Diamond styluses were not in general use in the same period when shellac records were being produced. That was just one of many.
Then, Verity is a terrible Mary Sue. At one point, Floyd (from 1959 Earth) volunteers to fly a spaceship - and is laughed at - but nobody has any problem with Verity flying it, even though she knew no more about such things than Floyd before her one previous flight. In fact, he's told "You can begin by telling me what you already know about matter/exotic matter coupling parities..." Really? At the beginning of the story, Verity barely even knew more than that such things exists, but apparently she's still expert enough to fly this ship. Give. Me. A. Break.
But the most evil problem with this book is that, while it can stand alone, it is clearly intended as book 1 in a series, and I absolutely hate getting taken in like that.