Right guys I've got a set of these spare... Cleats for Shimano SPD Pedals - SM-SH51
http://www.cyclexpress.co.uk/products/Shimano_Cleats_for_SPD_Pedals.aspx
Compatible with the Shimano M959, M646, M545, M540, M545, M540, M536, M520, M515, M505, M424, M324, M323, A520, A515The SH-56
Maybe...