V7.2.1

Site
---Product List
------Product 1
---------Sku 1
---------Sku 2
------Product 2
---------Sku 1
---------Sku 2

I have the following code which is attempting to display the first image in the gallery in each Product's Sku page on the Product List page:-

@inherits Umbraco.Web.Mvc.UmbracoTemplatePage
@{
    var productList = CurrentPage.Site().FirstChild("ProductList").Children("ProductItem").Where("Visible");

    foreach(var product in productList) {
        var skuList = product.Children.Where("Visible && DocumentTypeAlias == @0","Sku");
        var initialSku = skuList.First().sku;
    <section class="productpage-section">          
        <div class="row features-boxes product-border">
            <div class="col-l-3 col-m-3 col-s-3">
                <div class="productimg-lft ortac">

                    @foreach (var thisSku in skuList) {
                         if (thisSku.HasValue("productImages")) {
                            //var imageList = thisSku.GetPropertyValue("productImages");

                            //var imageList = thisSku.productImages.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);

                            var imageList = thisSku.GetPropertyValue<string>("productImages").Split(new string[] { "," },StringSplitOptions.RemoveEmptyEntries);                          

                            var productImage = Umbraco.Media(imageList[0]);
                            <img src="@productImage.GetResponsiveCropUrl("ProductUSP")" alt="@productImage.Name">
                        }
                    }
                </div>
            </div>
        </div>
    </section>
}

In the code above there are three attempts at getting the reference to the MMP. The first one:

var imageList = thisSku.GetPropertyValue("productImages");

Results in an error saying  "The value of parameter 'id' must be either a string or an integer". Fair enough, I obviously need to provide an ID to the Umbraco.Media(int) call.

The second one, which is an attempt to get an array of ID's from the MMP:

var imageList = thisSku.productImages.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);

Results in an error saying "Umbraco.Web.Models.DynamicPublishedContentList' does not contain a definition for 'Split'" which is a bit worrying on the face it, given other forum posts alluding to .Any being missed on previous builds of V7.x.

The third one:

var imageList = thisSku.GetPropertyValue("productImages").Split(new string[] { "," },StringSplitOptions.RemoveEmptyEntries);

Fails siliently. The page is displayed with empty img tags.

I'm at a loss as to what to try next. Any advice would be appreciated.

Craig