Adding a different background image for a page

I am working on a site that I’d really like to designate a separate background image, and header for one page within the theme.
The site is here:https://www.greenpeas.us/wordpress/ (Branfordmagazine theme)
I have included the background image in the stylesheet:

body {
background: #FFF url(images/barnwood2.jpg) repeat-x;
color: #333;
padding: 13px 0 25px 0;
}

I am wondering if this is a conditional tag moment; but would I need to do this on the index, perhaps referencing a “second” body, and creating the extra styling with 2nd background image in the stylesheet?

Thanks for any advise.