Hi,
If you use the Customize an Auctiva template, you can locate and copy - paste the base template HTML code to your own code editor (or eBay's) and remove the "guts". That's usually an inner table that contains the Auctiva [tags], i.e. I'm assuming it's the borders and background that you're wishing to use as a theme to reflect your Auctiva template enhanced listing pages. If there are credits for copyright, images, etc., I would leave those intact (visible).
Danno