I've come a bit stuck with this and, as far as I can see, it's the CSS that's messing things up. I'm confused as there are 2 style sheets being used by WP: reset-fonts-grids-tabs.css and style.css and I'm struggling to make it fit into my site layout and its CSS. Condensing 3 style sheets into 1 is more than my meagre brain can cope with.
The route I went down was adding my original header code to the WP header.php, rather than copying the root index.php code into an existing page as, I presume, you did. I tried this but couldn't make it display anything from WP!
Tony, can you give a bit more detail on how you dealt with the CSS side of things? Whether I take elements of the WP CSS and point the WP pages to my site CSS or add bits of my site CSS to the WP CSS, I can't get the page to look right.
Also, can you give a bit more detail on which files you actually changed?
This is how it looks at the moment and the attached screenshot shows that, before I started hacking at it with a sharpened Dreamweaver, it actually worked!
Thanks again.