Shop and Product page content width

Hi

Please see here https://www.artbyherbie.com/shop/

So far going great but a slight layout issue. I edited my theme years ago to include a second grey sidebar on the right. In doing so I narrowed down the content area to make space for the 2nd sidebar. I think css editing was involved as i narrowed down the content divs etc

The woocommerce shop and single page dont pull in this 2nd sidebar, which i usually declare in the template php. The cart and checkout pages DO include the 2nd sidebar so im thinking they either use post.php or a different template.

I’m happy not having the 2nd sidebar on the shop and product pages, but how can i increase the content area of these pages to cover the gap left over from the 2nd sidebar, ie the original dimension?

Is this a CSS issue? Can i override this for the WC pages only:
#content {
padding:30px 0 30px 0;
width: 530px
}
#content-page {
width:480px;
float:left;
padding:30px 0px 30px 50px;
clear:both;
}

But now I’m stuck with the 2nd sidebar showing underneath. How can I ‘undeclare’ the 2nd sidebar now?

Also, I’d rather woocommerce use a template where the 2nd sidebar is not included on ALL pages and the content width is increased, would this be an easier solution?