These people, Fidra Books, are going to be reprinting it during 2009.
C&p from an email I received today:
"Other books in the standard Fidra format next year will include Four Plus Bunkle by M Pardoe, Lost Lorrenden by Mabel Esther Allan and both Ghostly Term and Unforgettable Fifth at Trebizon by Anne Digby. The latter book has been clamoured for and I hope that I'll be able to persuade Anne to tell us a little of what happened to Rebecca and her friends in the 6th form. One of our highlights is Shores of Darkness, a previously unpublished title by Elinor Lyon which will be out in the summer."