You're a genius! Gottit!
However.......! Lol.
My alignments are all out!
The top and bottom are now aligning to the centre-left (IE starting from the left edge of the page-container and overhanging the right edge). (The page container is 966 wide and the top and bottom sections of the shadows are 1024)
And my newly defined css "page-shadow" box is ending before "customer_bottom", even though the div tags are closed after bottom.tpl in home.tpl.
Thanks
so so much for your help!
I'll get there eventually, lol.