I thought I had solved the problem by using the connecting cables from the old Tourer to the new. Silly me. Having taken the Harmony out I see the mass/mess of looms here. I had thought that there would be one simple direct loom (VUL 100310) that would connect from the back of the radio to the plug that lurks beneath the fuse box that connects to the CD. Below you can see that life is never that simple as it splits into the main harness.
However I have had a most welcome offer of this elusive loom which may or may not be the answer for a frustrated elderly gent.