Hi Eddie,
Do you mean that you don't want it show fully, right? As I can see that on your old site:
You already customized it by adding a container and custom CSS.
In the file: /templates/ja_diner/tpls/blocks/slideshow.php
Line 19, add 'container' class like this:
<div class="wrap t3-slideshow <?php $this->_c('slideshow') ?> container">
In the css file: /templates/ja_diner/css/custom.css, add this custom CSS:
.t3-slideshow.container {
max-width: 1250px;
}