Perch blocks - gallery with thumbnails?

An update:

So I can get the large images to display but I am having trouble with the thumbnails. For the main images I have the following code which works well:

<perch:blocks>
      <perch:block type="image" label="Image">
        <perch:before>
                <ul id="gallery" class="list-unstyled">
                </perch:before>
                  <li>
                    <a href="#slide<perch:content id="perch_item_index" type="hidden" />">
                      <img src="<perch:content id="slideImage" type="image" width="1000" label="Image" />" alt="<perch:content id="slideAlt" type="text" label="Image Description" size="xl" title="true" />">
                    </a>
                  </li>
                  <perch:content id="slideImage" type="image" suppress="true" width="200" label="Image" />
                <perch:after>
                </ul>
                </perch:after>
      </perch:block>
    </perch:blocks>

After the closing </ul> I need to take the values from the block item and list them as thumbnails. My template for this is:

<perch:before>
                <div class="thumb-box">
                    <ul class="thumbs list-unstyled">
                    </perch:before>
                      <li><a href="#<perch:content id="perch_item_index" type="hidden" />" data-slide="<perch:content id="perch_item_index" type="hidden" />"><img src="<perch:content id="slideImage" type="image" width="200" label="Image" />" alt="<perch:content id="slideAlt" type="text" label="Image Description" size="xl" title="true" />"></a></li>
                    <perch:after>
                    </ul>
                </div>
                </perch:after>

I think I need to use 'scope-parent' or layout the feature differently. I've tried quite a few options but everything has failed thus far.

Yes. In the block the user can select an image and add a description. The image is also re-sized to 200px wide. These images are displayed in a list.

Underneath this list I need to output the thumbnails (200px image) using the template shown above in previous post.

Whenever I try and do this using parent-scope="true" I seem to output the thumbnails in the wrong place or simply something odd happens.

I've never done this before as have always used perch_content_custom in pages to achieve. For this particular page I require this functionality to work within the template.

Large images work fine. It's just getting the thumbnails to show below that I am struggling with.