The company changed its name from Ryan Hotels plc to Gresham Hotel Group plc and was subsequently delisted back in 2004/2005 after being taken over by Precinct Investments.
Try contacting the company secretary at Gresham Hotel Group plc, 23 Upper O Connell Street, Dublin 1 or alternatively contact Computershare Investor Services Ireland Limited, Heron House, Corrig Road, Sandyford Industrial Estate, Dublin 18 (Tel 01-2163100) who acted as their share registrar and they should have your holding listed on the dissentors register.
The Precinct offer was accepted at €1.40 per share.