This is a steep learning curve....
Thanks guys for all your help.
I found my horn relay today (left it on steel relay bracket under plastic cover labelled up as "block b" stashed away in my bench).....LOL
Under this black cover there was only the one relay but as Stot's diagram shows there are 3.....
After having a quick look on the net it seems the "retracta relay" can be under the dash (as mine is) not with the horn relay and the "dim dip relay" is sometimes removed so the pop up headlights don't work on just sidelights.
So under my dash I have the "flasher relay" "open circuit relay" and "retracta relay"...... and not forgetting the fuse box.
I think now all I need to find is my "TNS relay" and "warning buzzer" which I'm guessing will probably be in the boot and in the left door panel...