Recently Viewed Widget - need product sku for image src

Question

My product images are served from https://website-list.s3.amazonaws.com/xxxxxx.jpg where xxxxxx is the product sku. I have created a module to change the Image URL on several templates, following the very useful instructions here: How to Change Product Images with external Image url in all magento 2 frontend and Backend Image display?. However it doesn't work for me on 2.4.2 for the minicart, checkout table and Recently viewed widget.

For the Recently Viewed I seem to need to edit: theme/Magento_Catalog/web/template/product/list/columns/image_with_borders.html and theme/Magento_Catalog/web/js/product/list/columns/image.js

In image_with_borders.html I changed the js function that is calling the image :

<img class="product-image-photo"
                     data-bind="attr: {src: getImageUrl($row()),
                                       alt: getLabel($row()), title: getLabel($row())}" />

to

<img class="product-image-photo"
                     data-bind="attr: {src: getNewImageUrl('160253'),
                                       alt: getLabel($row()), title: getLabel($row())}" />

And added a function in the image.js file:

getImageUrl: function (row) {
            return this.getImage(row.images).url;
        },
        
        getNewImageUrl: function (sku) {
            return "https://website.s3.amazonaws.com/" + sku + ".jpg";
        }, 

This works with a hardcoded sku but I need to be able to get the actual sku in the initial image_with_borders.html page, to send it through to the js file. How can I do that? All that's in that image_with_borders.html page to start with is:

<if args="isAllowed()">
    <a if="imageExists($row())"
       class="product-item-photo"
       attr="href: $row().url">
        <span class="product-image-container"
              data-bind="style: {width: getWidth($row()) + 'px'}">
            <span class="product-image-wrapper"
                  data-bind="style: {'padding-bottom': getHeight($row())/getWidth($row()) * 100 + '%'}">
                <img class="product-image-photo"
                     data-bind="attr: {src: getOBImageUrl('160253'),
                                       alt: getLabel($row()), title: getLabel($row())}" />
            </span>
        </span>
    </a>
</if>

How can I access sku from here? I tried $row.sku but that didn't work. Thanks!