Suddenly had a brainstorm as I typed in previous answer -There was also the Hertfordshire Maths Project in use in a lot of places so that might be it!
My other suggestions are-
Do you have a learning resource centre for teachers in your area?They may keep records of past booksor copies of books themselves for exhibitions etc
Each L..E.A will have a curriculum Maths advisor who could do some research for you I`m sure!Try Hertfordshire county council in Hertford