rare book find - copies of O'Neills of Ulster books saved from a skip

Last night a rare cloth-bound version of the valuable book The O'Neills of Ulster, their History and Genealogy by Thomas Mathews, originally published in Dublin Ireland at the start of the 20th centuary has been found in a skip in Vienna, Virginia, in the USA. It is believed the work were dumped along with a vintage copy of James Joyce's Ulysses and some rare poetry books by William Butler Yeats. I have checked on ebay and there is no sign of them appearing yet.