Only thing I can find (apart from your questions on abe and B&N) is a book called Captives of Time by Malcolm Joseph Bosse; have a feeling that's not it though. What sort of audience would it have been aimed at? Will keep trawling.
Still searching every now and then; know how frustrating it is to 'lose' a book! The best things I've come up with are Longitude by Dava Sobel and The Clockwork Three by Matthew J Kirby but the first seems too historical with no fantasy and the second is I think, a children's book.